THE STRATEGIES FOR EFFECTIVE TEACHING OF BIOLOGY IN THE SECONDARY SCHOOLS

CHAPTER TWO

REVIEW OF RELATED LITERATURE

2.1 Introduction

In this chapter, previous research woks and other related literature that assessed effects of concept maps and experimental strategies in teaching of biology in secondary schools are reviewed. The review is carried out to provide a frame work for some basic concepts and theoretical explanation of concepts that are fundamental to the study. Moreover, the review explored different researches on the field of study with the hope of determining the gap this will fill in terms of its contribution to knowledge. The review is therefore organized under the following sub-headings for easy referencing- Introduction, conceptual framework which is further discussed under concept maps, using concept maps in instruction, the use of concept maps and experiments in the teaching of Biology, origin of experimental science, importance of science practical work, experimentation in Biology teaching, Biology as a subject in Senior Secondary School, Biology curriculum for Senior Secondary School, Conventional teaching methods for Biology in Senior Secondary School, influence ofteaching methods on students‟ attitude towards Biology, influence of lecture method on students‟ achievement in Biology, influence of concept mapping on students‟attitude towards Biology, influence ofconcept mapping on students‟achievement in Biology, meaningful learning and retention, the need for a change in teaching strategy, theoretical framework, review of related empirical studies and summary of review of related literature.

2.2 Conceptual Framework

2.2.1 Concept Maps

Metacognitive strategies, as explained by Novak (1987) are strategies that empower the learners to take charge of his/her learning in a highly meaningful fashion. Concept mapping as a metacognitive instructional strategy based on Ausubel – Novak – Gowin theory of meaningful learning. (Ausubel, Novak and Hanesian, 1978; Novak, 1987; Novak and Gowin, 1984). It relates directly to such theoretical principles as prior knowledge, subsumption, progressive differentiation, cognitive bridging and integrative reconciliation. Concept mapping is based upon a major psychological theory in science education and is designed to help students learn how to learn science. Udeani and Okafor (2006). Concept maps were developed in 1972 in the course of Novak‟s research program at Cornell where he sought to follow and understand changes in children‟s knowledge of science (Novak & Musonda, 1991). Concept maps are graphical tools for organizing and representing knowledge, they include concepts usually enclosed in circles or boxes of some types, and relationships between concepts indicated by a connecting line linking two concepts. Words on the line, referred to as linking words or phrases and these specify the relationships between the two concepts. Novak and Canas (2006); they defined a concept as a perceived regularity in events or objects, or record of events or objects designated by a label. Concept maps are represented in a hierarchical fashion with the most inclusive, most general concepts at the top of the map and the more specific, less general concepts arranged hierarchically below. Concept maps were developed to enhance meaningful learning in sciences. They serve to clarify links between old and new knowledge and force the learner to externalize those links. Concept maps are useful tools to help students learn about their knowledge structure and the process of knowledge construction (Meta knowledge). In this way, concept maps also help students to learn how to learn (Meta learning).

Qarareh (2010) outlines the advantages of concept maps to include the following:

• They can be used as advance organizers to improve learner‟s achievement (Kommer 2004).
• Provide teachers with meaningful and practical structured approach.
• Aid the development of deep meaningful teaching, moving towards critical thinking rather than surface approaches.
• It allows students to reflect on their own misunderstanding and take ownership of their learning (Fitzgerald, 2004).
• Organize their thoughts and visualize the relationship between the key concepts in a semantic way (Pill, 2005).

Okunlola and Wahab (2011) asserted that concept mapping is very useful in the teaching and learning process for systematizing and organizing not only the concepts under study, but also the already learned concepts. They believe it is used for building a new system for the measuring of our external world. The approach they concluded if properly adopted will:

• Promote better retention and understanding of the subject matter, also concept details are easily reconstructed from a map; this reduces the burden on memory and thus reduces memorization errors.
• It shows the organizational structure of content as a compact source of information.

• It is a versatile teaching tool that can be used to present and reinforce content or assess its understanding.
• It supports students in making connection between known information and new information.
• By creating maps, students clarify their understanding of the topic and integrate new ideas into their thinking.
• It aids students in summarizing texts and identifying main ideas as well as provide a useful way to assess students‟ understanding of a topic.

Novak (1998) stressed that the process of concept mapping can reduce the need for rote memory and make learning more meaningful. Johnson and Otis (2006) suggested that concept mapping should be treated as a very personal learning tool. According to whitehead (2008) in Young (2008) one of the primary goals in the use of concept map is to promote meaningful learning. In order for this to occur the following points need to be considered:

• The learner must have relevant background knowledge.
• Materials to be learned must be conceptually clear and presented with simple language and examples that will relate to the learner‟s prior knowledge.
• The learner must make the choice to learn meaningfully. Students must be motivated to incorporate new meanings into their prior knowledge, rather than just memorizing concept definitions. The creation of concept maps supports the incorporation of new meanings into prior knowledge.

2.2.2 Using Concepts Mapping in Instruction

The use of concept maps in instruction on a specific topic helps to make the instruction “conceptually transparent” to students. Many students have difficulty identifying the important concepts in a text, lecture or other forms of presentation. Part of the problem stems from a pattern of learning that simply requires memorization of information, and no evaluation of the information is required. Such students fail to construct powerful concept and prepositional frameworks, teaching them to see learning as a blur or myriad facts, dates, names, equations or procedural rules to be memorized. For these students, the subject matter of most disciplines, and especially science, mathematics, and history is a cacophony of information to memorize, and they usually find this boring. Many feel they cannot master knowledge in the field. If concept maps are used in planning instruction and students are required to construct maps as they are learning, previously unsuccessful students can become successful in making sense out of science and any other discipline acquiring by a feeling of control over the subject matter. (Bascones & Novak, 1985; Novak, 1991, 1998); Jegede et al 1990; Trowbridge and Bybee (1996).

According to the “dual-coding” Theory of Information Storage, Paino (1991), information is processed and stored in memory in two forms: a linguistic form (words or statements) and a non-linguistic form (mental pictures or physical sensations). The way knowledge is coded in a brain has significant implication for teaching and particularly for the way we help students acquire and retain knowledge. As Marzano, Pickering and Pollock (2001) point out, “the primary way we present new knowledge to students is linguistic. We either talk to them about the new content or read about it” (p.73). The fact that education gives weight to the verbal processing of knowledge means that students are left to generate their own visual representations. Yet, it is a well established that showing students how to present information using the Imagery Form not only stimulates but also increases activity in the brain (Marzano 1998). As students try to convey what they know and understand in non-linear, visual ways, they are forced to draw together what they have learned, see how ideas, information and concepts are connected; develop higher-order thinking skills (e.g. analytical thinking); and makes sense to others. Visual representation also helps students remember and recall information more easily.

Visual representations can be created and supported by tools such as graphic organizers, physical models, pictographs (i.e. symbolic pictures) and engaging students in Kinesthetic activities that involve physical movement (Marzano, Pickering & Pollock, 2001). From those, perhaps the most commonly used visual learning tool is graphic organizers which include diagrams depicting hierarchical information (e.g. concept maps). Graphic organizers not only help students not to “read” and comprehend more easily complex information and relationships but also generate ideas, structure their thought and learn how to make visible in an easy-to-read way, what they know. The latter requires that students understand the topic under study, be able to discern relationship between concepts and prioritize information. Birbili (2006).

2.2.3 The Use of Concept Mapping and Experiments in the Teaching of Biology

Concept maps are constructed to represent visually “meaningful relationships among concept in the form of propositions” (Novak and Gowin, 1984, p.15). As Novak and Canas (2006) explain propositions are statements about some objects or events in the universe, either naturally occurring or constructed. According to Birbili (2006) concept maps are the spatial representations of concept and their interrelationships that are intended to represent the knowledge structure that humans store in their minds”

(Jonassen, Reeves, Hong, Harvey and Peter‟s as cited in McAleese, 1998, p.258). Concept maps can facilitate teaching and learning in several ways. First, as their inspirers note, they can help both teachers and students to identify the key concepts and principles that they must focus on for any specific task (Novak & Gowin 1984, p.15) in Birbili (2006). Second, a concept map can provide “a kind of visual road map” indicating some of the pathway that teachers may take “to connect meanings of concepts in propositions” (Novak & Gowin 1984, p.15). Third, concept maps can provide a graphical summary of what students have learned, which in turn can help teacher detect and eventually break down students‟ misconceptions and misunderstandings.

Concept maps are also effective in helping teachers identify students‟ prior knowledge and understanding and organize teaching and learning in a way that is meaningful to them. In fact, identifying students‟ pre-existing knowledge was the aim that leads

Novak and his team to the construction of the first concept map (Novak, 1998). Novak

& Gowin 1984, p.15-16) argue that “because meaningful learning proceeds most easily when new concept or concept meanings are subsumed under broader, more inclusive concepts, concept maps should be organized in a hierarchical way; that is the more general, more inclusive concepts should be at the top of the map, with progressively more specific, less inclusive concepts arranged below them”.

Figure 2.1: Concept Maps on Characteristics of Living Things.

Source: STAN biology workshop journal 2011

Both simple and more complex concept maps consist of two things: concepts are usually represented as labeled circles or boxes, which are called “needs”. Relationships, on the other hand are represented as lines or arrows connecting the concepts, while arrows are used to show the direction of the relationship. As concepts are connected through links, they form the statements that Novak & Gowin refer to as propositions.

Birbili (2006) proposed that if concept maps arc to fulfill their potential as a teaching tool, children‟s need and cognitive abilities need to be taken into consideration. More specifically, Birbili said educators interested in using concept maps should keep in mind the following:

1. Young children need to be taught the strategy of concept mapping, Sparks Linfield and Warwick (2003). They should be taught the strategy over of a period of direct instruction before they can successfully construct their own concept maps (Ferry, 1997). The process should start by having children observe their teacher creating concept maps.
2. When modeling the process of concept map creation, teachers should give particular emphasis to the linking or joining words and help children understand that

“they are what makes the whole thing have meaning” (Sparks Linfield & Warwick, 2003, p.126). Those words help create the propositions, the main characteristic of concept maps.

1. Concept maps should be introduced after children have had many opportunities to manipulate real objects, observe what is going on around them, record their observations, and communicate their findings and impressions in different ways. Having those experiences is important because it is through these experiences that concepts and generalizations are formed (Mancinelli, Gentih, Priori & Valitutti, 2004).

Concrete experiences are also crucial for the development of representative thinking.

For example, children must have observed plants needing to be watered and seen for themselves what happens to be able to represent graphically the relationship “plants need water”. It is also better to introduce concept maps after children have had some experience with simple, less-structured graphic organizers such as webs as a way of summarizing and presenting information.

1. Children‟s first attempt to create a concept map should be done within the context of a simple familiar topic (e.g. animals or plants) and using a small number of concepts, for example a concept with two to four links. Figures 4 and 5 show two examples of the kind of concept map that sparks Linfield and Warwick are referring to:

Figure 2.2: Example of a simple concept.

Figure 2.3: Another example of a simple concept.

Source: Sparks and Warwick (2003)

Kinechin (2000a,b) discussed the positive import of using concept maps on instruction and learning in secondary biology education. Building on the researches conducted, Kinechin (2000b) demonstrated the relevance of concept mapping for a teacher planning and preparing a lesson and creating an opportunity for meaningful learning on behalf of students.

Kinechin (2000b) found a positive effect on students‟ who used concept maps to revise and summarize materials using experiments or practical activities in the teaching of biology to provide opportunities for students to actually do science as opposed to learning about science. Nwezi (2008) asserted that practical activities can be regarded as a strategy that could be adopted to make the task of a teacher (teaching) more real to the students as opposed to abstract or theoretical presentation of facts, principles and concepts of subject matter. Nwezi maintained that practical activities should engage the students in hands on, minds on, activities using varieties of instructional materials/equipments to drive the lesson home.

Shulmen and Tamir‟s (1973) in Abimbola (1994) review of research in science

teaching,dentified three rationale generally advanced by those that supported the use of the laboratory in science teaching. They included:

1. The subject matter is highly complex and abstract.
2. Students need to participate in enquiry to appreciate the spirit and methods of science.
3. Practical work is intrinsically interesting to students.

Shulman and Tamir also compiled a list of objectives of using laboratory work in science teaching. The list included the teaching and learning of skills, concepts, attitudes, cognitive abilities, and understanding the nature of science.

2.3 Origin of Experimental Science

The use of laboratory method in science teaching originated from the ideas of early scientist (Abimbola, 1996). The 17th century is very significant in this respect.

Mendelson (1982) has characterized the century as the century of “The Scientific Revolution”. This characterization is so because, according to Westfill (1971). “It was in the 17th centur that the experimental method became a widely employed tool of scientific investigation” (p.115). The general feeling of disillusionment among scientist with earlier methods precipitated this trend (Butterfield 1957; Westfall 1971). The feeling of disillusionment had to do with results of scientific investigations that did not match the efforts put into them. The scientists of the time blamed the method of conducting science for low output.

Taylor (1963) claimed that “the idea of experimental science began to have influence about 1590” (p.90) when scientists started basing their work on deliberately contrived experiments. According to him, “Galileo Galilei (1564 – 1643) in Abimbola (1996) was the first to employ the modern scientific method in the fullness” (p.91) in physics and astronomy. Before then, Westfall (1971) stated that Gaten‟s writing on physiology contained examples of experimental investigation. Westfall also claimed that Robert

Grosseteste of the medieval school and the logicians based at the University of Padua, Italy in the 11th century, also discussed the precursors of hypothetico-deductive method.

However, it was in the 17th century that scientists paid the greatest attention to the scientific method that led to a revolution in science. The sheer number of persons that attended to the method then, indicated the need for an acceptable method of conducting science. Francis Bacon (1961 – 1626) was perhaps the first in the 17th century to formulate a series of steps to account for the scientific method in his book Novum organum (The New Instructments, 1620), Taylor (1963). The book was a reaction to Aristotle‟s treatise in logic referred to as organum. Bacon based his method on inductive method of objective observation and experimentation without any preconceptions. Rene Descartes‟ (1569 – 1650) Discourse on method based on mathematical reasoning and deduction closely followed Bacon‟s book. Westfall (1971) has credited Robert Boyle with perhaps the best statement of the experimental method that focused on “the activity of investigation that distinguishes the experimental method of modern science from” (p.115). Pascal, Gassende and Newton also wrote on scientific method (Westfall 1971).

The emphasis on method during this period paid off with the several discoveries and inventions in the 17th century and beyond thereby giving the impression, albeit unintentionally, that science is synonymous with its method.

2.3.1 Importance of Science Practical Work

Shulman and Tamir's (1973) review of research on science teaching identified three rationales generally advanced by those that supported the use of the laboratory in science teaching. The rationales included: (1) The subject matter of science is highly complex and abstract, (2) Students need to participate in enquiry to appreciate the spirit and methods of science, and (3) Practical work is intrinsically interesting to students. Shulman and Tamir also compiled a list of objectives of using laboratory work in science teaching. The list included the teaching and learning of skills, concepts, attitudes, cognitive abilities, and understanding the nature of science. Also, there is hardly any science method's book that does not usually list the objectives of science laboratory work (Abdullahi, 1982; Collette & Chiappetta, 1984). All science curricula in Nigeria list practical activities that should go with each curriculum item listed. The current West African Examinations Council (WAEC) syllabus and the National Educational Research council (2009),Federal Ministry of Education for Senior Schools, recommended that the teaching of all science subjects listed in the syllabus should be practical based, perhaps, to demonstrate the importance it attached to practical work in science. Thus, several decades of emphasizing the assumed importance of laboratory work in science teaching have elevated the importance to the level of a dogma. Thomas

(1972) and White and Tisher (1986) are of this opinion. This position perhaps, is why Yager (1981) thought that science educators should treat laboratory work as the 'meal'the main course" (p. 201) rather than an "extra" or "the desert after a meal" (p.201). Also, Bajah (1984) said, "All science teachers and students know that practical work is the 'gem' of science teaching" (p.44).

This dogma about the importance of laboratory work originated from the views of a few American educationists in the early sixties that extolled the importance of laboratory work in science teaching. Notable among these personalities according to

Abimola(1996) are Bruner (1961), Gagne‟ (1963), and Schwab (1960), they all extolled the virtues of teaching science as a process of inquiry or discovery. Before them, Dewey (1938) advocated learning by doing through his "project method" that he considered as a method of organizing the school curriculum on a scientific basis. Another American, Charles Pierce (Peirce, 1877, 1958) who advocated the use of the method of science as a mode of inquiry to satisfy our doubts, in turn, influenced him. The ultimate goal of these advocates of practical work was to train students in the ways of practicing scientists so that students could become good scientists in the future. The surprise by which the former Soviet Union took the Americans, and, perhaps, the world, in launching the Sputnik into space in 1957, motivated their positions. Emphasis in science teaching at this time shifted from the products of science, what science to teach and learn, to the processes of science, i.e., how we teach and learn science (Bates, 1978). According to Shulman and Tamir (1973), this shift in emphasis lacked empirical evidence because the influence of the educationists mentioned above formed the basis of the shift. As a result of this influence, and the need to match the Soviet feat, the Americans commissioned and executed several curriculum development projects. Such curriculum development projects included the Biological Science Curriculum Study, which started in 1959-, Chemical Bond Approach, began in 1958, Physical Sciences Study Committee, was initiated 1956, and Science: A Process Approach which started in 1967, etc. They were all laboratory based. These curriculum development activities, with emphasis on laboratory work, spread to Nigeria, and elsewhere in the world.

2.3.2. Experimentation in Biology Teaching

Experimentation is a method of learning science concepts not through what the teacher told the students, but through what is involved in the process of investigation, carrying out experiments as well as other practical activities. The experimental teaching strategy also referred to as discovery in STAN (1998) involves observing, classifying, measuring, predicting, describing, hypothesizing, experimenting and inferring. Experimentation involves activity-oriented learning; in this case, the emphasis is on doing. Most time the activities are carried out in the biology laboratory. A laboratory is a room or building set aside for scientific investigations.

Practical activities in biology provide opportunities for students to actually do sciences as opposed to learning about science. Nzewi (2008) in Nwagbo and Chikelu (2011) asserted that practical activities can be regarded as a strategy that could be adopted to abstract or theoretical presentation of facts, principles and concepts of subject matters. Nzewi maintained that practical activities should engage the students in hands-on, mind-on activities, using varieties of instructional materials/equipment to drive the lesson home. Nwagbo (2008:41) in Nwagbo and Chikelu (2011) stated that:

“The use of practical activities (approach) to the teaching of biological concepts should therefore be rule rather than an option to biology teachers. If we hope to produce students that would be able to acquire the necessary knowledge, skills and competence needed to meet the scientific and technological demands of the nation”.

Experimentation is a means by which students acquire meaningful learning of science concepts to the point of achieving transfer and application of knowledge. Hence, it exposes them to acquire attitudes and skills of a scientist. This method of teaching science has proved to be one of the most effective ways of learning. (Nigerian Open University Edu 636: Biology methods).

The laboratory work involved in the process of experimentation can be broken down into different phases:

1. Pre-laboratory session: This involves assembling in advance by the teacher all the equipment and materials needed for the exercise, so as to ensure that they are all in good working condition. The teacher also trial tests the chemicals to be used to ensure that they are active and this session reduces the errors which the teacher may have committed in the actual laboratory session.
2. Laboratory session: In this session, the teacher interacts with the students by telling them what to do, the teacher oversees by walking round the laboratory to ensure students follow instructions they are given carefully and also clarifies any doubt or problem.
3. Post laboratory session: In this session, the teacher discusses the result of the investigation in order to clarify students‟ doubt. The teacher also summarizes the result of the investigation and assign marks to the work done by students.

The advantages of experimental in the teaching of biology include:

1. It enables students to have direct sensory experience of scientific knowledge, e.g.

working with living organism; it enables the learner not only to acquire knowledge but also to appreciate life.

1. It fosters opportunities for the acquisition of science process e.g. manipulation, measuring, classifying etc.
2. It helps in the retention of information as the students interact with the scientific process.
3. The use of experiments helps students to develop scientific altitudes such as enquiry, curiosity, carefulness, objectivity, honesty etc.
4. Experimental work helps to stimulate and sustain student‟s interest in science.
5. It aids students in problem solving and arriving at conclusions.
6. It helps to increase student‟s ability towards critical thinking and acquisition of better understanding of scientific knowledge.

Realizing the importance of science process skills as a solution to scientific problems, the Federal Government among other things states as one of the national goals of education in Nigeria that “Education should aim at helping the child in the acquisition of appropriate skills abilities and competencies, both mental and physical as equipment for the individual to live in and contribute to the development of the society” (Federal Republic of Nigeria (FRN), 2004:29).

2.4 Biology as a Subject in Senior Secondary School.

Biology according to Nwagbo and Chukelu (2011) as a branch of science and the prerequisite subject for many fields of learning contributes immensely to the technological growth of nature. This includes medicine, pharmacy, forestry, agriculture, biotechnology and nursing. The authors further stated that the study of Biology in senior secondary school can equip students with useful concepts, principles and theories that will enable them face the challenges before and after graduation. Biology in senior secondary school is offered for the three-year senior secondary school. It involves mainly the study of plants and animals. In most schools, Biology is compulsory for all science students and optional for Arts and Humanity classes. The topics offered in the course of these 3years prepare the students for higher education in any of the biological related course.

The Senior Secondary School according to the National Policy of Education (2004) shall be comprehensive with a core-curriculum designated to broaden pupils‟ knowledge and outlook. The senior secondary school Biology curriculum is one of such curriculum materials. The Biology curriculum at the directives of the Federal Government is for the societal and individual development and has its cardinal objectives. The preparation of pupils to acquire:

1. Adequate laboratory and field skills in Biology.
2. Meaningful and relevant knowledge in Biology.
3. Ability to apply scientific knowledge to everyday life in matters of personal and community health and agriculture.
4. Reasonable and functional scientific altitude FRN (2004)

In pursuance of the stated objectives, the contents and context of the curriculum place emphasizes on field studies, guided discovery, laboratory strategies and skills along with conceptual thinking. The curriculum is intended to provide a modern Biology course as well as meet the needs of the learner and the society through relevant and functional contents, methods, processes and applications. It covers the major themes of:

1. Organization of life
2. Organisms at work
3. The organisms and its environment
4. Continuity of life.

These themes are of direct relevance to the society and the learner.

In planning the new Biology curriculum, the spiral approach to sequencing a science course was adopted. In the approach, the concepts to be taught are arranged in such a way that they run throughout the three-year post basic course, with the concepts being discussed in greater depth as the course progresses. (NERDC, 2009).

2.5 Conventional Teaching Method for Biology in Senior Secondary School

Teaching has been defined in many ways by different authors. Akudolu (1994) in Onuigbo (2011) defined teaching as a deliberate effort by a mature or experienced person to impart information, knowledge, skills and so on to an immature or less experienced person through a person that is morally and pedagogically acceptable. Fadare (2004) defined teaching as the action of someone who is trying to assist others to reach their fullest potentials in all aspects of development. Lyop and Mangut (2001), defines teaching as a process that facilitates learning. Owoso (2005) stated that the aim of teaching is to facilitate learning, stressing that there are many teaching methods and strategies used by teachers in teaching students. Various authors have listed many teaching methods used in teaching, but specifically, the Biology methods of National Open University has specified the lecture method, discovery, discussion methods, demonstration, project method, and field trip as conventional methods of teaching Biology.

For a teacher to communicate the knowledge in a topic to the pupils, the teacher needs to decide what teaching method or strategy to use. Teaching method is defined as an overall plan for the orderly presentation of content or learning material, and usually a method is driven by a philosophy about how children learn. Lecture method according to Lyop and Mangut (2001) is characterized by a steady flow of information from teacher to the students, the teacher dispenses facts and opinions about procedures or contents, expressing his own ideas or citing an authority. Oyetunde and Famwang

(1996) stated that the philosophy behind a lecture method is that the knowledge the teacher has can be passed on to students. Ogwa (2002), states that lecture method of instruction is the process of speaking to students, while they sit and listen to the teacher. Ogwa further emphasized that in lecturing method, the teacher acts as a conference organizer while the students listen as the audience. The lecture method is the most common of these traditional teaching methods.

Bligh (1993) observed that originally, lecturing was the only way that knowledge stored in the books could be transmitted to a large number of students. The word lecture is derived from the Latin legere meaning to read. Bligh states that many centuries after the invention of movable type and other significant advances in technology, learning continues to be the primary mode of instruction in secondary schools as well as in higher education. According to the author, reasons for lecture method are because lectures are cheap since teachers can lecture in auditorium full of students. Lectures are easily changed and updated and they are efficient in covering material quickly. Finally and perhaps most importantly, the method is familiar to students and teachers alike and their roles are clearly defined.

Lyop and Mangut (2001) points out the inherent setbacks of lecturing method. They affirm that it does not promote meaningful learning as it appeals only to the sense of hearing. According to them more effective learning goes on only when many senses are involved. They opined that schools consist of many ability groups in each class, the abilities of student they believed vary considerably therefore, and they conclude the lecture method cannot meet the different needs of the students. They believe that some students learn better through the manipulation of objects while others will learn easily through hearing and seeing objects and events. Lecture method they opined encourages rote learning and regurgitation of information without necessarily aiding understanding.

The lecture method they stated is unsuitable for teaching science in secondary school and is better suited for teaching in higher institutions of learning.

A survey carried out at Dorset House school of occupational Therapy, Oxford into the perceived effectiveness of different teaching methods used within the lecture format in the human biology course of year 1 & 2 by Butler (1992) showed that the traditional didactic lecture method was perceived by students as the least effective method used, yet by involving the students actively within the lecture time, the format was enhanced and was regarded as a more effective teaching and learning tool. Experimental tasks and learning package used within the lecture format were also perceived by students as effective.

A similar study by Ozay, Ocak and Ocak (2009) on sequential teaching methods on Biology showed that evidence from a number of disciples suggests that oral

presentation to a large group of passive students contributes very little to real learning. In Physics, they opine that standard oral lecture does not help most students develop conceptual understanding of fundamental processes in electricity and in mechanics. Similarly, student grades in a large general chemistry oral lecture do not correlate with the lecturing skills and experience of the instructor. Despite the limitations of traditional oral-lectures, introductory science courses in biology are forced to offer high-enrolment introductory science courses many professors who teach these courses feel that

lecturing is their only option.

The study by Ozay, Ocak and Ocak (2009) came to the conclusion that academic achievement of students taught using experiment and slide demonstration was higher than beginning with lecture method. They agreed that using only oral lecture bores students and looses their attention. They concluded that people remember 10% of what they read, 20% of what they heard, 30% of what they saw and 90% of what they had a hands-on-experience. Laboratory work is a hands-on experience (Beydogan, 2001). And since Biology and other science courses are practical oriented it consequentially means that oral lecture method may not be completely avoided but should not be solely used in any science instruction.

The increasing effect of globalization and the rapid rate of technological changes in the world have informed the recommendation of UNESCO and ILO (2002) that all systems in the 21st century should be geared towards life-long learning. This requires that schools should in addition to academic skills, inculcate values to citizen such as problem solving collaborative skills and higher order thinking skills. Okoye and Okechukwu (2006) opines that science educators have been focusing attention on how to improve science instruction in schools by going beyond the stereotype methods of obtaining knowledge in science. There has been emphasis, they said in science teaching and on students‟ active involvement in doing science. Concept mapping teaching strategy they stated is designed to help students acquire basic scientific skills and improve performance.

Another teaching method is the demonstration method. Lyop and Mangut (2001) define it as the act of showing, displaying something, according to them, it involves showing something for the students to see. They stated that demonstration method is normally done by teachers but sometimes demonstrations can be performed by students individually or in small groups. According to Alfred (1973) in Lyop and Mangut (2001) the demonstration method serves various purposes in teaching. These purposes include setting a problem, illustrating a point (which is the most popular use of demonstration or to serve as a climax) – performing on exciting students which is an excellent way to end a lesson.

Lyop and Mangut list the following reasons as justification for the use of demonstration method:

1. It gives opportunity for use sophisticated apparatus and difficult experiments.
2. Hazardous and dangerous experiments can be carried out.
3. It is effective for teaching manipulative and applied practical skills.
4. It guides students‟ thinking along the same channel.

In using demonstration method for instruction, Okoro (1999) pointed out that for demonstration to be effective, the teacher should:

1. Plan the demonstration
2. Prepare students for demonstration
3. Carry out the demonstration process and re-state the important point connected

with it.

Demonstration can be carried out in the class or done in groups as group demonstration can also be an individual demonstration. It is possible for students to learn how to perform manipulative operations by reading or being told how to do them. However, they can learn faster and more effectively when they are shown how the work is done.

Demonstration enhances students‟ rate of comprehension of specific objectives.

Another method used for instruction is field trips. Lyop and Mangut (2001) define it as an excursion taken outside the classroom for the purpose of making relevant observations and also for obtaining some specific information. The experience they said provide direct, primary and concrete evidences to the learner. When field trips are properly planned Lyop and Mangut opines it offers the students opportunities for observing, collecting, classifying, studying relationships and manipulation of objects. Field work is very important in any effective science instruction. It is one of the most enjoyable and exciting experiences of students studying science. It plays the same role as laboratory experiments and demonstrations because through the process one can gain first hand-experiences.

Lyop and Mangut list the advantages of field trips to include:

i.Speedy contributions to science programme ii.These are related to the out of school or real life experiences of the student than the classroom experiences.

1. It creates meaningful learning and allows easier application of learning to real

life.

1. Likely to arouse varied type of interest in students‟ work with actual objects which are likely to generate curiosity than ideas do
2. Helps to add reality to, and verification of scientific laws.

The project method according to Lyop and Mangut (2001) is employed by teachers for individual instruction. This method is meant to provide for the needs of individual students, or sometimes small groups so that those with special abilities have opportunities to fulfill themselves. The project work is one of the teaching methods for the teaching of biology. Project method is suitable for large groups, small group and individual instruction (Okoro 1999, Ukoha and Eneogwe (1996). Ukoha and Eneogwe (1996) explained that the project method of teaching originated in the early twelfth century. It was greatly influenced by Dewey‟s problem method of teaching and it is an original work of W.H Kill Patrick who advocated purposeful activity, problem solving and the needs and interest of the individual child in action, learning and conduct. The underlying principle of the method according to them is that learning takes place through direct contact with materials. A project method implies a practical problem which a student and the teacher plan to execute.

The planning and the execution must be concrete in nature. It should involve the design, arrangement of materials, availability of equipment and tools and a good environment for the activity. On the part of the teacher he/she must have an excellent understanding of the individual after learning has taken place. The execution should meet the following objectives to encourage the individual, to assist the individual for specific changes. It is a learning activity selected, planned, designed and executed by learners collectively or individually to clarify facts, acquire knowledge, skills, appreciation and to solve identified problems under the teacher‟s guidance and supervision. Therefore the role of the teacher in providing guidance and direction to students should not be completely eliminated. This is because students tends to exaggerate their power of execution and to select projects that are beyond them leading to production of crude projects which defeat the purpose of project work. According to Lyop and Mangut (2001) topics from project works can be obtained from interaction with their colleagues, reading from Journals and classroom experience on a particular topic.

In summary, conventional teaching methods are teacher-centered approaches of learning. They are methods used in teaching many subjects including Biology, but to meet the globalization demands, modern teaching methods such as concept mapping amongst others should be explored for use in teaching Biology if it will yield a good effect.

2.6 Influence of Teaching Method on Students’ Attitude towards Biology Attitude according to Macmillan English Dictionary for Advanced Learners (2007) is someone‟s opinion or feelings about something especially as shown in their behaviour. Nasr & Asghar (2011) opines that definition or concept of attitude towards science is vague and ambiguous, but sees attitude as a concept that defines emotional trends in response to affairs, person, locations, events or ideas. Simpson and Oliver (1990) believe that phrases as “I like science enjoy science courses” conveys attitude e of the learner.

Nasr & Asghar (2011) outlined that many factors influence attitude and achievement motivation among adolescents. Some of these factors are associated with parental background and family environment, individual characteristics such as self concept, locus of control and achievement motivation, school influence such as class climate, teachers and administrative styles. According to Osbome, Simon & Collins (2003), studies have incorporated a range of components in their measures of attitude to science including: the perception of teachers; anxiety towards science; the value of science; self esteem at science; motivation towards science, enjoyment of science; attitude of peers and friends towards science; attitude of parents towards science; the nature of the classroom environment, achievement in science and fear of failure on course. According to Yara (2009), attitude of the teacher and his method of teaching can influence students‟ attitude. Simpson and Oliver (1990) in Alebiosu and Micheal (2011) identified factors of teachers‟ attitude, teaching methods and personality, attitude of parents and peers, nature and perception of the subject among components influencing attitude to school subject. This is because attitude is key to success as people used to say, Fansceca (2010) opined that one of the factors affecting students‟ learning performance is the way they face knowledge, namely their attitude to the subject. Such attitude as profound feelings, relatively stable attitudes are derived from positive or negative experiences across time on learning the subject (Estrad, 2002 in Fonseca,

2010). This experience according to Omirin and Oladosun (2010) includes teachers‟ method of teaching.

Goodykoonz (2009) citing Pophama (2005) opined that in education, research suggests that students‟ attitude towards a subject leads to academic success. This is why the research seeks to find out the attitude of students to the use of experiments and concept map in the teaching of Biology.

2.6.1 Influence of Lecture Methods on Students’ Attitude towards Biology

Biology teaching must reflect the exciting nature of the subject and its surrounding.

Students‟ work in Biology lessons should be practical and visual in nature whenever possible. Yok (1996) in Egitimbilim (2009). Ericson (1960) in Egitimbilim (2009) stated that the lecture method is the method of teaching outside of manipulation work. Teachers are comfortable with traditional method because they remain in control of content and time (Havice, 1999).

According to Armbruster, Patel, Johnson and Weiss (2009) the traditional lecture format of most large introductory science courses present many challenges to both teaching and learning. Although the traditional lecture course may be effective for effectively disseminating a large body of content to a large number of students. This one way exchange often promote passive and superficial learning (Bransford et al 2000) and fails to stimulate student motivation, confidence and enthusiasm (Wieimer 2002). A study conducted by Egitimbilim (2009) showed that lessons with lecture method bores student and makes them lose their attention. Supporting the above result National Research Council (2007) and wright and Boggs (2002) opines that the traditional lecture method can often lead to students completing their undergraduate education without skills that are important for professional success. Armbruster et al (2009) in their study observed that the perceived deficiencies common to traditional lecture based introductory courses was poor student attitudes. These attitudes were reflected by poor attendance, limited participation in class and sub-optimal student performance. In conclusion, when an active-learning and student-centered pedagogy was incorporated into a previously traditional lecture-based introductory biology course. The changes led to sustainable improvements in students‟ attitudes and performances. The lecture method should therefore not be a main method of teaching and learning in Biology.

2.6.2 Influence of Lecture Method on Students’ Achievement in Biology Methodology is very vital in any teaching-learning situation. The method adopted by the teacher may promote or hinder learning. The adoption of lecture methods by most teachers according to Ameh and Dantani (2012) in order to overcome the bulky syllabus before the SSCE affects students‟ performance. According to the authors, researchers believe that in the lecture method, theory is taught as an absolute knowledge, hence pupil-centered activities for developing scientific reasoning skills and processes are lacking. The lecture method is also known to cause lack of interest and poor performance in science as opined by Njoku (2007) in Ameh and Dantani (2012). Aghadindno (1987) in Ameh and Dantani (2012) contented that science teaching

limited exclusively to telling, reciting and testing of information is sterile as it does not convey either the meaning or intent of science. Derek (2007) in supporting this view in Ameh & Dantani (2012) reported the seriousness of the deplorable performance of secondary school students in science subjects and identified persistent use of the traditional mode of instruction as one of the major short-coming affecting the learning and higher achievement in science subjects.

In studies carried out by Ameh & Dantani (2012), McAdmins (2001), Osuafor & Okigbo (2013), they believe that the use of lecture methods of teaching has been found not to be appropriate with respect to achievement in the learning of science.

2.6.3 Influence of Concept Mapping on Students’ Attitude towards Biology The attitude formed by a child towards any subject will go a long way to decide and determine the child‟s choice and achievement in that subject as well as his or her career choice (Woolnough, Guo, Leite, de Almeida, Ryu, Womg and Young, (1997) in Alebiosu et al (2011 . Simpson and Oliver (1990) in Alebiosu et al (2011) identified factors of teacher attitude, teaching methods among others, as factors that influence attitude of students to school subject. The above, according to Alebiosu et al (2011) explains that teachers are very important dominants of enrolment, achievement and essentially attitude towards school subject. The teacher is a consultant, guide, mentor, inspirator and moderator (Krejster, 2004) in Alebiosu et al (2011). His/Her use of innovative instructional strategy stands a higher change of positively influencing the attitude of the learner to the subject. Guzel,( 2004) in Nasr & Asghar (2001)believes that negative attitude towards a subject makes learning or future learning difficult, hence when students are positively inclined towards a subject they tend to do well in that subject.

Consequently Grober and Jodl (2010) in Alebiosu et al (2011) suggested the use of self study; problem oriented learning and remote lab/web experiments, while Adeoye and Okpala (2005) in Alebiosu (2011) advanced the systematic assessment procedure.

Alebiosu et al (2011) opines that invariable, instructional strategy and teaching methods are important determinants of attitude to science (Orji, 1998; Meltzer, 2002; and Alebiosu,( 2006). One of such is the concept mapping instructional strategy. Concept mapping relates with the meaningful learning theory whose advantage lies on the fact that learning a new knowledge is dependent on what is already known. By using concept maps, the learning process becomes active rather than passive. Kempa and Dude (1974) in Adesoji (2008) worked on the influence of science instruction; the result was that attitude becomes more positive after instruction. Also Studies from Long, 1981; Atwood, 1978; and Wasik, 1978 in Adesoji (2008) suggest that there is relationship between attitude and methods of instruction and also between attitudes and achievement.

Reviews of concept mapping studies have shown that the strategy has been generally perceived as having a positive effect on learning Horton et al, 1993; lawless et al, 1998 in Kinchin, 1992.

2.6.4 Influence of Concept Mapping on Students’ Achievement in Biology Metacognitive strategies, as explained by Novak (1987) are strategies that empower the learner to take charge of his or her own learning in a highly meaningful fashion. Concept mapping as a megacognitive instructional strategy is based on Ausubel NovakGodwin theory of meaningful learning. (Ausubel, Novak & Hanesien, 1978). It relates directly to such theoretical principles as prior knowledge, subsumption progressive differentiation, cognitive bridging and integrative reconciliation. Concept mapping is based upon a major psychological theory in science education and designed to help students learn how to learn science. Studies on the influence of concept maps on students‟ achievement has shown that students taught using concept map achieved significantly higher than taught using lecture method. Boujaound & Altieh(2008),

Candan, Turkmen & Candak (2006), Egolum & Nwafor (2012), Karakuyu (2010), Okoye and Okechukwu (2006). Studies from Okoye & Okechukwu, 2006; Ige, 1998; and Wandersee 1990, shows that when incorporated into teaching, it helps to improve students‟ performance.

Meaningful learning is the learning that is well anchored and integrated in the cognitive structure. It occurs when the learner can find meaning in the information presented. Meaningful learning will not occur unless the new ideas are presented in a clear way that enables them relate with other ideas unless the learner already possesses those other ideas he can relate the new ideas with and unless the learner actually makes a conscious attempt to do so. As a result of meaningful teaching, the new idea will remain anchored to a so called subsumer (anchoring site of the ideas)Novak & Gowin(1984),Novak (1991b) Young (2008). According to Novak and Canas (2006) meaningful learning requires three conditions:

1. The materials to be learned must be conceptually clear and presented with language and examples related to the learner‟s prior knowledge
2. The learners must possess relevant prior knowledge
3. The learners must choose to learn meaningfully. The one condition over which the teacher or mentor has only indirect control is the motivation of students to incorporate new meanings into their prior knowledge, rather than simply memorizing concept definition or propositional statements or computational procedures

According to Ausubel “the most important single factor influencing learning is what the learner already knows” (Novak, 1998, p.71). Relationships between concepts are formed when two concepts overlap on some level. As learning progresses, this network of concepts and relationships becomes increasingly complex. Ausubel‟s compare meaningful to rote learning which refer to when a student simply memorizes information without relating that information to previously learned knowledge. As a result, new information is easily forgotten and not readily applied to problem-solving situations because it was not connected with concepts already learned. However, meaningful learning requires more effort; as the learner must choose to relate new information to relevant knowledge that already exist in the learner‟s cognitive structure. This requires effort initially. However after knowledge frame-work are developed, definitions and the meanings for concept become easier to acquire. Further, concepts learned meaningfully are retained much longer, sometimes for a life time. Knowledge creation is viewed as a special form of meaningful learning.

According to Momoh-Oke (1997) retention is viewed as the repeat performance by a learner of the behavior than an acquired piece of knowledge which is always intended to elicit in the learner (without practice) after an interval of time. Retention simply refers to how much a person remembers after an interval of time without practice and this is the difference between what is initially learnt and what is later forgotten. Haynie (2003) defines retention as learning which lasts beyond the testing and is assessed with tests administered two or more weeks after the information has been taught and tested. Haynie further explained that retention of learning is measured with two tests: The initial test and the delayed retention test. The initial test is the test employed at the time of instruction or immediately thereafter while the delayed retention tests are those tests administered two or more weeks after instruction and initial testing to measure retained knowledge.

Oloyede (2010) in his research work examined the effect of guided discovery and concept mapping teaching strategies on SSS students‟ chemistry achievement. The result showed that there was a significant difference in the retention of the two groups used for the research in favour of the group taught using concept mapping. This finding according to Oloyede is in agreement with those of Okebukola (1990) and Udeani (1993). Altin (2002) in his work on the study of computer assisted experimental method and concept mapping method with regards to some cognitive processes and level of Retention observed that the use of concept mapping in teaching physics courses had positive and significant effect on the level of retention of students.

2.7 The Need for a Change in Teaching Strategy in Biology

A lot of factors have necessitated the need for a change in the teaching strategy or strategy in Biology. Among these are the effects of globalization and the rapid rate of technology changes and the need to address individual differences more seriously in the classroom .In addition to these is the persistent failure in both internal and external examinations of biology students Teaching and learning process should be student centered and one way to bring about a change of emphasis in teaching from the teacher centered approach to a facilitated approach is to change the method of instruction (Kearsley, 2010). This shows that Biology education needs a total overhaul in terms of its medium of instruction. Teachers should utilize appropriate strategy to pass across knowledge and enhance achievement, interest and retention. That is the teachers should consider every topic and select the correct method that will convey the knowledge at a particular time to the students.

According to Neekpoa (2007) in Onugbo (2011) ,Nigeria is saddled with educational problems of great magnitude, which the traditional methods of teaching and learning alone cannot solve. Roegge, Wenthing and Bragg (1996) stressed that the traditional approach of delivery of knowledge and skill through lecture must be improved or even abandoned and replaced with methodologies which allow students to learn needed skill in the context within which the skill are suited in the real world. There must be a change in the conventional lecture methods adopted in teaching students to a more fascinating strategy that could enhance good performance. This study therefore adopted the use of experiments and concept mapping strategies asalternative strategies in the teaching of

Biology in senior secondary schools.

2.8 Theoretical Framework of the Study

This research is hinged on the following theories of learning.

1. The operant conditioning models and stimulus Response (SR), Association theory
2. Jean Piaget‟s development theory
3. Bruner‟s theory of cognitive learning
4. John Dewey‟s theory on experience, reflection and learning
5. Ausubel‟s subsumption theory

2.8.1 The Operant Conditioning Model and Stimulus Response Association Theory

In a school setting, the frequency of various behaviors can be seen as depending on the immediate consequences of those behaviors. For example, if a biology student perform well in an examination and the student is rewarded with praise or gift or any other motivating factors, the student will tend to repeat the performance. According to Stoner (1982) the operant conditioning process may be expressed as stimulus- response- consequences – future response. The above means that individual‟s own voluntary behavior (Response) to a situation or event (Stimulus) is the course of specific consequences or outcomes. If a teacher uses a strategy or strategy that gives the student proper understanding, the student will tend to have interest and retain more of what is been taught in that subject. If the teaching strategies or strategy is difficult or abstract for the student, the student tends to loose interest and avoid such subjects.

This suggests that if a Biology teacher intends to arouse students‟ interest in the subject, the teacher must use a teaching strategy or strategy that aids in retention of concept which invariably improves students‟ performance, thereby making learning attractive and interesting one of such strategies is the use of concept maps and experiments in the teaching of biology.. The operant conditioning theory by B.F Skinner was highly acclaimed to be affective in training of lower animals.

2.8.2 Jean Piaget’s Development Theory

Piaget‟s theory is based on the idea that the developing child actively and adaptively builds cognitive structures, in other words mental “maps” schemes or networked concepts for understanding and responding to physical experience within his or her environment. Through successive stages of intellectual development children develop intellectual structures that enable them to have a greater understanding not only of the world, but also themselves. Piaget considered intellectual activity to be a biological function. In his theory; Piaget describes the development and adaptation of mental operations or thoughtstructures for example counting, classification etc which progress through rich interactions with the world. Concept maps and experiments in Biology help students to progress through such interactions. Piaget‟s theory of conceptual change involves four stages of intellectual development.

Sensorimotor stage (birth – 2years old), pre-operational stage (age 2-7), Concrete operation (age 7-11) and formal operations (Beginning at age 11-15). Reasoning is freed from the concrete. Adolescents begin to construct whole systems of belief and can engage in more reflective reasoning such as thinking about other‟s thoughts or engaging in self reflection. In scientific problems solving, formal thinking enables adolescents to systematically manipulate variables and reason about unknowns such as algebraic variables. This stage of intellectual development can be of use to the students in the construction of concept maps as concept maps help learners to make evidence the key concepts or propositions to be learned and suggest connections between new and previous knowledge.

2.8.3 Bruner’s Theory of Cognitive Learning

Bruner‟s theory states; “To perceive is to categorize, to conceptualize, to learn is to form categories, to make decisions is to categorize”(p:25), He maintained that people interpret the word in terms of similarities and differences and suggested a coding system in which people have a hierarchical arrangement of related categories. Each successively higher level of categories becomes more specific. The major variable in his theory of learning is the coding system into which learners organize, this coding system. He believes that the system facilities transfer; enhance retention and increase problem solving and motivation. He also advocated the discovery oriented learning method in schools which he believed helped students discover the relationship between categories.

2.8.4 John Dewey’s Theory

John Dewey‟s theory emphasizes the experiential aspects of learning. In his theory learning results from our reflections on our previous experiences, as one strive to make sense of learning task. Dewey believed that the role of education is neither to cater completely to a learner‟s inclinations nor to attempt to force upon a child a pre-ordained curriculum which takes no account of the learner. This is what the conventional strategies in teaching of biology does. He saw children‟s mind as flexible, expansive and unformed. Educators should structure learning environment that engage children in inquiries, which he believes will guide then towards broader knowledge.

2.8.5. Ausubel’s Theory of Subsumption

This is also referred to as Assimilation theory or Theory of Advanced organization. The theoretical framework for this study is based on this cognitive learning theory. Concept mapping is grounded in Ausubel‟s Assimilation Theory (Ausubel, 1968; Ausubel, Novak & Hanesian, 1978 in Bamidele ,Adetunji,Awodele&Irinoye 2013). Assimilation theory posits that new knowledge can be learned most effectively by relating it to previously existing knowledge. Concept Maps may be viewed as a methodological tool of assimilation theory that displays fundamental elements of the theory such as subsumption, integrative reconciliation and progressive differentiation. Concept Maps allow for the representation of non-hierarchical relationships or cross-links, as well as other types of non-hierarchical arrangements. Over the past decades, Ausubel (1963) has been concerned with the problem of how meaningful verbal learning and retention can be facilitated through the use of extrinsic organizing devices that modify the learner‟s cognitive structure. He stressed that if existing cognitive structure is clear, stable, and suitably organized, it facilitates the learning and retention of new subject matter. However, if it is unstable, ambiguous, disorganized, or chaotically organized, it inhibits learning and retention. In order to describe the importance of classification in learning and retention and the strategy for deliberately manipulating cognitive structure so as to enhance proactive facilitation and to minimize proactive interference, Ausubel

(1963) coined the phrase “advance organizer” this involves the use of appropriately relevant Inclusive introductory materials that are maximally clear and stable in a learning situation. These organizers are normally introduced in advance of the learning material itself and are used to and establish a meaningful learning set. The advance organizers help the learner to recognize that elements of new learning materials can be meaningfully learned by relating them to specifically relevant aspects of existing cognitive structures. The rationale for using organizer is based primarily on the importance of having relevant and otherwise appropriatly established ideas already available in cognitive structure. It is also to make logically meaningful new ideas potentially meaningful and to give them stable anchorage. The organizer functions to

„bridge the gap‟ between what the learners already knows and what he needs to know before he can meaningfully learn the task at hand. It is to provide ideational scaffolding for the stable incorporation and retention of the more detailed and differentiated material that follows. This is the basis of this research study. The concept maps were introduced in advance of the learning materials to facilitate the establishment of meaningful learning set.

The central propositions in Ausubel‟s cognitive assimilation (subsumption) theory (Ausubel, 1968; Ausubel,Novak and Henesain ( 1978) ,the main basis for concept mapping,are:

1. Concepts derive their meanings through their inter-connections with other concepts; and
2. Meaningful learning occurs when fresh knowledge is consciously anchored to relevant concepts in the Cognitive structure of the learner.

According to Wandersee (1990), concept mapping relates directly to such theoretical principles as prior knowledge, Subsumption, progressive differentiation, cognitive bridging and integrative reconciliation. This theory involves the learner linking new specialized concepts to more generalized, more inclusive concepts in the learner‟s existing structure of Knowledge (schema). The result of subsumption is that the Schema of the learner becomes progressively more differentiated leading to assimilation of newer information. This theory, therefore, asserts that cognitive structure is hierarchically organized and more inclusive, broad concepts are super-ordinate to less inclusive and more specific concepts. Furthermore concepts in the learner‟s cognitive structure undergo progressive differentiation in which greater inclusiveness and specificity of concepts are discerned, resulting in recognition of more prepositional linkages with other related concepts (Canas et. al. 2003).

A student may not remember a name he learnt previously but when the bearer of the name is physically present, he may recall. Idialu (1998) and Ughamadu (1998) are in agreement with the above explanation. They identified the roles that instructional strategy can play in learning and teaching of subjects. This situation mostly applied to factual knowledge where recognition is much more difficult to recall. The theory stipulates that an experience gained in one situation may be incompatible in another situation because of the absence of vital clues.

Implication of the theories to the study

The present study on effects of concept mapping and experimental strategies in teaching Biology is based on John Dewey‟s theory on experience, reflection and learning and also on Ausubel‟s theory of subsumption.

John Dewey‟s theory emphasized the experiential aspect of learning .He suggested a learning environment that would provide ample” time, talk and tools”. He suggested learning environments that engaged children in inquiries. The students used in the present study were taught Biology and allowed to learn through inquiry and also were allowed to handle tools/materials/equipments needed for the experiments they performed. Thus this study was basically anchored on John Dewey‟s theory of experience, reflection and learning.

Ausubel‟s theory of subsumption also called assimilation theory or theory of advanced organizer posits that knowledge can be learned most effectively by relating it to previously existing knowledge. This existing knowledge Ausubel emphasize can be brought to bear by helping the learner through the introduction of an advance organizer to recognize that element of new learning materials can be learned meaningfully by relating them to specifically relevant aspects of their cognitive structures. The students used for the study were tutored on how concept mapping works and on commencement of treatment were presented with concept mapping instructional package (CMIP) ahead of the lesson to help them organize their cognitive structure to the prior knowledge they have on the topic under consideration so as to enable them connect the new knowledge to what they already know. Thus this study is also basically anchored on Ausubel‟s theory of subsumption.

2.9 Empirical Studies

The following related literatures were reviewed, the purpose of the review was to determine what gap this present study will fill and its contribution to knowledge.

Okoye and Okechukwu (2006) they examined the effect of concept mapping and problem solving teaching strategies on achievement in genetics among Nigeria secondary school students. The method used for the study was a quasi-experimental pre-test and post-test treatment design one hundred and thirteen senior secondary three

(SS III) students were selected from three mixed secondary schools located in Delta North Senatorial District in Delta State as subjects for the study.

The experimental group was taught using selected topics in genetics using concept mapping and problem-solving strategies while the control group was taught using the traditional lecture method. The instrument used for data collection was the Genetic Achievement Test (GAT) consisting of 40 multiple choice items and 20 short answer questions on Genetics. The reliability index of this instrument was 0.82. To answer the research questions, analysis of covariance was used. The result revealed that students exposed to concept mapping strategy while studying genetics achieved significantly higher than those exposed to the traditional lecture method. The reviewed work is closely related to the present study in that both are tackling how to improve the problem of poor performance in Biology. The population of the research will be a little higher than the present study been reviewed. The research under review took into consideration only a single topic while this present research used five topics in the course of this study.

Udeani and Okafor (2012) carried out a research on the effect of concept mapping instructional strategy on the Biology achievement of senior secondary school learners. One hundred and twenty four biology slow learners were identified and randomly assigned to the expository group (n = 62) and concept mapping group (n = 62) respectively were taught the concept of photosynthesis. From the purpose of the hypothesis concept mapping instructional strategy could produce significant (<P 0.05) gain over the expository instructional strategy in Biology attainment of slow learners amongst others. The groups were post-tested after two weeks of teaching for any significant difference in their Biology achievement. A 30 –item multiple pretest and posttest were used to collect the data and a t-test was used to test the hypotheses. Analysis of the post-test scores indicated that the group taught by the concept mapping instructional strategy performed significantly (p < 0.05) better than their expository group counterparts. The result of data analyzed for the study, provided support for the potency of the concept mapping strategy in bringing about meaningful learning of biological concepts in slow learners. The present study sought to find out the potency of concept mapping not only on slow learners, but on a generality of all types of learners. A retention test was conducted two (2) weeks after treatment to test the level of students‟ retention of concepts taught after two (2) weeks of lesson.

In a study carried out by Boujaoude and Attieh (2007) on the effect of using concept maps as study tools on achievement in Chemistry had the following objectives to (1) examine whether or not the construction of concept maps by students improves their achievement and ability to solve higher order question in chemistry (2) investigate the differential effect of the treatment by gender and achievement level and (3) explore the relationship between performance on concept and achievement level. The participant for the study were sixty grade 10 chemistry students in Lebanon who were randomly divided into two sections based on achievement to experimental and control groups. The materials covered were acid-base titration and equilibrium in weak acids. The instrument used for data collection was a chemistry achievement test which measured a pre and a post test. The study spanned a period of eight weeks in a class that met four times a week. The data obtained was analyzed using means, standard deviations and Analysis of variance (ANOVA) .The Result showed that while there were no significant differences on the achievement total score, there were significant differences favoring the experimental group for scores on the knowledge level question. The study is similar to the present study as a pre and post tests was also administered but unlike the former, the present study this study has a higher population, and also tested for retention and attitude. It also taught five topics in to the students in five weeks using experiments and concept mapping for instruction.

Ajaja (2011) examined if the use of concept mapping as study skill can influence students‟ achievement in Biology. The design of the study was quasi experimental pretest, post-test control group design. The population consisted of 100 SSII from Delta state were used for the study. To guide the study five research questions were raised and three hypotheses stated and tested at 0.05 level of significance. The major instrument used for data collection was Biology achievement test and an interview scheduled to determine the students‟ perception of the usefulness of concept mapping in their studies. The study spanned a period of six weeks. The data was analyzed using Analysis of covariance (ANCOVA) and paired sample t-test.The major findings of this study include, a non significant difference in immediate post achievement test scores between students who used concept mapping as a study skill and those who reviewed and summarized in their studies. It was concluded that concept mapping could serve as an appropriate alternative for studying Biology. The population used for the present study is similar to that of this study under consideration, as SS II students will also be used in the study. The instrument used was the pre-test and post-test Biology achievement test. This study did not consider if concept map helps in retention of Biology concepts. This study opted for this.

Akeju, Rotimi and Kenni (2011) investigated the effects of teaching with concept mapping strategy on learning achievement in Nigeria secondary schools. The research study adopted the Quasi-experimental Research Design. The population comprised of a sample of 168 senior secondary school class two physics students purposively selected from senior secondary school across Ekiti state. There were two activity groups, the experimental and control groups. The research study were two types, namely uncompleted MCM ( Motion Concept Map) which the experimental group were required to complete, and used as pre-test and post-test respectively and printed materials which comprised of two parts. 20 simple structured sample questions relating to the knowledge of the presented concept was used to measure level of cognition and part B consisted of 10 structured questions administered as post-test to the experimental group only. The post-test for both groups was administered two weeks after the treatment mean, standard deviation and t-test were used to calculate students‟ achievement. The major findings of the study were that:

i.There is a significant effect of the instructional strategy on students‟ learning achievement ii.Experimental group was able to recall a higher percentage of learned materials.

Akeku,Rotimi &kenni (2011) used a population similar to that used by the present researcher, however the researcher did not use students‟ across FCT. The present research used five (5) weeks for the study after which a post-test was given, unlike the research under consideration which gave a post-test after two weeks only. The researcher used twenty-five (25) multiple questions for the pre-test and post-test.

Karakuyu (2010) investigated the effect of students‟ concept mapping on their physics achievement and attitudes towards physics lesson. The design for the study was comparative research that employed an experimental group and a second group that was taught in a more traditional teacher-centered manner called the control group. Subjects were 58 ninth grade students from the two classes enrolled into general physics in a high school in Turkey. The data were collected via a pre and post administration of the physics Achievement Electricity test (PAET) and concept maps attitude scale towards physics (CMASTP). One of the classes was randomly chosen as experimental group

(28), which constructed electricity concept and the other was control group (30) which did not receive any presentation on concept mapping. The study conducted in six weeks in a class that met two times a week. The material covered was about electricity. The data was analyzed using mean, standard deviation, independent sample t-test and a two –way ANOVA. The result from the study using t-test showed that while there were no difference in the attitude and achievement between the experimental and control groups, however, the experimental group students were observed to have a tendency of more positive attitude than the control group students. Results also showed that drawing concept map instruction was more effective than traditional instruction in improving physics achievement of the participating students. This study under consideration did not research the effects of concept maps on students‟ retention which the study considered. The research was conducted for five (5) weeks unlike this present study which was conducted for six (6) weeks, the class also met two (2) times a week like the study under consideration.

Rao (2004) carried out a study on the Effect of Concept Mapping in Science on Science Achievement, Cognitive Skills and Attitude of Students. The objective of the study included among others to develop and implement concept mapping as a strategy in the selected few units of science standard VIII students and its effect on the achievement, concept attainment and process skills of students belonging to different intelligent groups. The study was quasi-experimental in nature where non-randomized pre and post test design was used. The intact classes of eight standard as a whole were considered as experimental (47) and control group (42) for the study from two local schools of Mysore City. The instruments used to collect data were achievement test, a process skill test and a concept attainment test. The data obtained was analyzed using percentages, mean, standard deviation, t-values and ANOVA. The major finding of the study revealed that the experimental group student had performed better when compared to the control group.

The present study did not take into consideration the cognitive skills of students‟ to concept mapping, but only on its achievement in Biology and not in science. The study is similar to that of the researcher because intact classes of SS2 students were used in schools. However the population of the researcher was larger than that of the study under consideration.

Candan, Turkmen and Cardak (2006) carried out a study on Effects of Concept

Mapping on Primary School Students‟ Understanding of the Concept of Force and Motion in Turkey. The purpose of the study was to reveal fifth-grade school students‟ misconceptions about the concepts of force and motion and to compare the Effect of Traditional Teaching Methods and Concept Maps in remedying these Conceptions. The research was designed as a quasi-experimental approach that concept maps and traditional teaching methods were applied to the experimental and control groups, respectively. The study approximately took six weeks. A thirty-item was constructed for the purpose of identifying the students‟ understanding and misconceptions concerning the concepts of force and motion. The study indicated that the students in the experimental group, taught with concept maps, showed greater achievement in the unit than the students in the control group training with the traditional method.

The study under discourse is similar to the study the researcher is undertaking because both sought to compare the effectiveness of concept maps with traditional teaching method. The researcher will also be using intact classes like the study under discourse and will equally use experimental and control group. The study is however different from the researcher‟s in that the research will be carried out using secondary school students, using five (5) concepts instead of the two used and last for five weeks instead of six weeks used in the study above. The research compares the Effects of Concept Maps alone with Traditional Methods, while the present research used specifically, compared concept maps and experiments with the traditional lecture method.

Egolum (2012) investigated the Effects of Concept Mapping and Cognitive Styles on Achievement of Students in Chemistry. A quasi-experimental design was used. The focus of the study was to compare the mean achievement scores of field dependent(FD)

and field independent(FI) students taught chemistry using concept mapping(CM)instructional strategy and those taught using conventional lecture method(CLM) amongst others. Two research questions and two hypotheses were posed to guide the study. The quasi-experimental design was used. One hundred and ninety three (193) chemistry students were selected from four co-educational schools in

Onitsha. Two instruments: Group embedded figure test (GEFT) and Chemistry Achievement Test(CAT) were used. The data were analyzed using mean, standard deviation and analysis of covariance (ANOVA). The results revealed that Field Dependent (FD) and Field Independent (FI) cognitive styles students taught chemistry using concept mapping achieved better than those taught using conventional lecture method. The population for this study is similar to the researchers‟ population and unlike the study; the researcher is using intact classes and not students selected like the present study. The research is similar to this study, because the researcher will also use the lecture method for its control group. This present study sought to find out what effects concept mapping has on students‟ achieivement and retention. The study also covered more than one topic hence was similar to the present study.

A study on attitude of Nigerian Secondary School chemistry students towards concept mapping strategies in learning Mole Concept was administered by Bamidele, Adetunji, Awodele and Irinonye (2013). It compared the effectiveness of the use of different concept mapping strategies used as advance organizers on students‟ performance and examined attitudes of students towards the use of concept mapping strategies in the teaching of five topics. The treatment lasted five weeks of two periods per week. The study adopted the pretest-post test-control group quasi experimental design. The population for the study was 132 SSII chemistry students randomly selected from three

(3) secondary schools in Osun state. Two research instruments were used for the study, Problem Solving Achievement test in Chemistry (PSATC) and Questionnaire on attitude of student towards concept mapping (QACSCM).The data collected were analyzed using one way analysis of variance (ANOVA). The result of the study showed that students had a positive attitude to concept mapping strategy. The research is similar to this study, in that the researcher also used five weeks for treatment and equally met for two periods in a week and also adapted the quasi experimental method study also considered the change in the attitude of students towards Biology; however instead of one topic used in the research been examined, the researcher used five (5) topics and also had a higher population.

A study on the Attitude towards Biology and its effects on student‟s achievement was conducted by Nasr & Asghar (2011) using a total of 185 grade 12 students in Isfahen. A 30 item questionnaire provided by authors based on STAQ_R inventory was used for the research and the research questions among others included: Is there any relationship between attitude towards Biology and students‟ achievement in Biology courses at the following dimension (a) motivating Biology class;(b) self directed efforts;(c) family models;(d) biology is fun for me (e) peer models. The data was analyzed using the statistical software SPSS version 16.0 t-testThe result showed that among attitude towards science dimensions only “biology is fun for me” had meaningful and positive relation with students achievement in biology. This study is similar to the one been carried out by the researcher in that the researcher sought to find out the attitude of students to Biology only this time, the research is using concept maps and experiments unlike the researcher under study who is not using any teaching method

2.10 Summary

So far, the review presented a moderate analysis of studies that relate to the framework for some basic concepts that are fundamental to the study. Moreover, the review explored different works on the field of study and some related field of study with a view to determining the gap which this study will fill in terms of contribution to knowledge. in the review, the theoretical framework used included operant conditioning model and stimulus response (SR).Association theory, Bruner‟s theory of cognitive learning, John Dewey‟s theory of cognitive, Ausubel‟s subsumption theory other review done covered the following concept maps, using concept maps in instruction, the use of concept maps and experiments in the teaching of Biology, origin of experimental science, importance of science practical work, experimentation in Biology teaching,

Biology as a subject in Senior Secondary School, Biology curriculum for Senior Secondary School, conventional teaching methods for Biology in Senior Secondary

School, influence of teaching methods on students‟ attitude towards Biology, influence of lecture method on students‟ achievement in Biology, influence of concept mapping on students‟attitude towards Biology, influence ofconcept mapping on students‟achievement in Biology, meaningful learning and retention, the need for a change in teaching strategy, review of related empirical studies. In the view of the reviewed authors, it was revealed that students performed better when exposed to the use of concept mapping as an instructional strategy than when they are taught with conventional method alone. It was also showed attitudinal changes when concept maps were used for instruction In the review of empirical studies some result findings on the effectiveness of the use of concept mapping and academic achievement in Biology, Chemistry and Physics showed that students instructed with concept maps usually performed better and retained better.

However the effectiveness of using concept mapping and experimental teaching strategy in Biology is yet to be determined and ascertained it is clear from the review of literature that concept mapping has been used mostly in the teaching of a single topic in Biology or in the other two science subjects. It therefore become necessary that the present be embarked on to investigate the effectiveness of using concept mapping and experimental teaching strategies in teaching Biology.