'Theory' is a word traced back and/or widely regarded to have been derived from a Greek word theoria, meaning "contemplation" or "speculation". However, a theory can be defined as a structure analytically designed to explain and identify a set of distinct observations as a class of occurrence and make essential assertions about the underlying reality that brings about or affects this class. In learning of science, a number of theories have been proposed, but the theories are fundamentally categorized into three: constructivism, behaviourism and cognitivism. Behaviourism mainly focuses on the objectively and distinct observable learning aspects. On the other hand, Cognitive theories of learning do look behavior and beyond to provide a detail of brain-based learning. With regard to constructivism, learning is largely viewed as a process whereby the learner is involved actively and does constructs or builds principles and/or concepts that are new. All these three categories do explain and postulate different learning models that can be developed or incorporated in the curriculum to make perception of science ideas or concepts kind of soft, real and attainable by learners especially those at their secondary school level of learning.
2. Constructivism and cognitive development
2.1 Constructivist approach
Constructivism is a learning theory that views learning as a step by step process in which the learner participates actively and establishes new concepts and/or ideas based upon his or her experiences of the world or surrounding. As a matter of explanation, according to constructivists, "learning involves formulating one's personal knowledge from one's personal experiences." The Constructivist theory of learning is indeed a quite personal endeavor, in which concepts, laws, rules, facts, theories, and general principles which are internalized by the learner may as a result be subjected to practice in the real-world context by the very learner. Such a scenario can also be referred to as social constructivism. According to Social constructivists, knowledge is formulated or constructed when an individual does engage in social talk and activity about problems shared. Learning is viewed as that process by which an individual is introduced into a culture by a more skilled and knowledge members (DeVries et al., 1994). Constructivism theory itself does possess numerous variations. The variations include: Active or participatory learning method, discovery learning method as well as knowledge construction. Without regard to the differences, Constructivism does promote the learner's free adventure and exploration within a given schedule, framework or structure. The teacher's role is merely to guide and facilitate. The teacher also encourages the learners to discover and develop principles for themselves and on their own and by extension construct or build knowledge by working intensely to solve real problems. Many evident aspects of constructivism are found in learner centered or self-directed learning, transformational learning, experiential learning, situated cognition, and reflective practice.
2.2 Cognitive development
Cognitive approach is one of the popular leaning models given due attention by most psychologists, especially the Gestalt psychologists. It is viewed to have two underlying key assumptions: that an individual's system of memory is an actively organized information processor and that initial or background knowledge plays a great role in learning. Cognitive theories do attend to behaviour and beyond to explain learning based on brain. Cognitivists do consider greatly the way human memory operates to enhance learning. For instance, the physiological processes involved during sorting and encoding of information as well as events in both short term and long term memories are very crucial to educators who work under the cognitive learning theory. The Gestaltists do firmly hold that the main point of control over learning activity does lie with the individual learner. Today, many researchers are narrowing on topics such as cognitive load and information processing theory. These learning theories are of great use since they do guide instructional design. Other aspects of cognitive learning found in learning include: how to learn, acquisition of social role, intelligence, learning, and relationship between memory and age.
2.3 Piagetian model
Piaget did discover that children generally think and reason in a differently way at different periods in their lives. He strongly believed that everyone had to pass through a sequence of four very distinct stages. The four stages include: sensorimotor stage - usually from birth to 2 years; preoperational stage- from 2 years to 7 years; concrete operational stage- from 7 years to 11 years; and finally formal operational (abstract thinking) - 11 years and above(Evans, 1973). Every stage has a major mental task to be accomplished. For example, in the sensorimotor stage, the cognitive structures are mainly restricted to the mastery of concrete or tangible objects. The mastery of signs and/or symbols usually occurs in the second stage whereas the concrete stage has learners tasked to master classes, relations as well as numbers and by extension how to reason. The final stage deals mainly with the mastery of thought (Evans, 1973). Piaget's theory of development involves the learner's active participation. That knowledge is not merely transmitted via verbal means but must be built and rebuilt by the learner himself. Piaget did assert that for a child to understand and duly construct knowledge of the world, such a child must act on and interact with objects and it is such actions and interactions which provide knowledge of the objects to the child (Sigel, 1977). He added that the mind of the child arranges and organizes reality and acts upon it. According to Piaget, for learning to occur the learner must be active and participate in the learning process. Wanda states:
Piaget's approach to learning is a readiness approach. Readiness approaches in developmental psychology emphasize that children cannot learn something until maturation gives them certain prerequisites. The ability to learn any cognitive content is always related to their stage of intellectual development. Children who are at a certain stage cannot be taught the concepts of a higher stage.
Students learning science
In learning science, the students are not just empty slated. They do have useful idea from their background. The problem only arises when they are dealing with the relationship between their prior knowledge and the science concepts. Most students always have difficulty linking concepts with real things and therefore are subject to misinterpretations of science concepts.
Their views of science
Students do have varied views on similar or same thing. This situation is owed to their different knowledge background. It is further compounded by their diverse and varied interests. Certain concepts in science are profoundly and commonly misconstrued by a majority of students. They include such concepts as: weight and mass, force and acceleration etc. Much other knowledge in science does appear difficult to comprehend and relate to real life situation like charge, quite abstract to the learners. Constructionists would require the students to make-up on their own by relating the knowledge with commonly observed items whereas cognitivists demand from the learner the ability to take in new information as well as that of arranging and organizing the knowledge in a coherent manner.
Reasons why students might experience science as difficult to learn
Several reasons explain why learners do encounter difficulty when learning science. They range from colour identification to language, background, interest, motivation, nature of the learner, etc.
The nature of the learner
The learner is a very unique entity in education. Social constructivism views an individual learner as a unique person with unique needs and backgrounds. The learner is also seen as complex and multidimensional. Social constructivism not only acknowledges the uniqueness and complexity of the learner, but actually encourages, utilizes and rewards it as an integral part of the learning process (Wertsch, 1997).
The importance of the background and culture of the learner
Constructivism theory encourages the student to make an independent conclusion prompted and informed by his or her background, culture or worldview. Symbol systems like language are usually inherited by learners and the culture is learned throughout the learner's life. It therefore stresses the significance of the nature of the learner's interaction with knowledgeable societal members. In absence of social interaction with more skilled and knowledgeable people, it is not possible to get social meaning of crucial signs and understand how to manipulate and utilize them. Children form their thinking abilities just by interacting with their colleagues, adults and the surrounding. From the constructivist viewpoint, it is hence important to consider the background as well as culture of the student throughout the process of learning. Background also aids to shape and form the knowledge and absolute truth that the student creates, discovers and gains in the process of learning (Wertsch 1997).
The motivation for learning
Another significant assumption with regard to the nature of the learner concerns the degree and motivation source for learning. According to Von Glasersfeld (1989) obtaining and sustaining motivation to learn from a learner is strongly dependent on the student's confidence in his or her potential for learning.
The role of the instructor
Instructors do act mainly as facilitators. According to the constructivist approach, instructors have the responsibility to adapt and play role of facilitators and not teachers (Bauersfeld, 1995). A teacher provides a didactic lecture that contains the subject matter whereas a facilitator assists the student to understanding of the content. In teaching, the learner's role is passive while a facilitator ensures that the learner has played an active role during the process of learning.
How science is taught in schools
Science can be taught through deductive or inductive means. The more suitable of the two dominant science teaching methods is deductive method. The deductive method permits learners to interact with the apparatus or specimen and this aspect of learning enhances retention of the concepts learnt. Learners are given all the materials they need and the teacher's role here is merely to guide and let learners manipulate the apparatus to obtain required data or information.
4. From theory to practice
4.1 Typical didactic activities in the early -years science curriculum
4.1.1 In UK
In the early years, the ideas of the constructivist were never widely valued and embraced due to the dominant perception in the larger public that children's play was considered aimless and of no or little significance if any. Piaget disagreed with these old outdated views, however. He regarded play as a crucial and necessary component of the learner's cognitive development and did provide a science-based evidence for his opinions. Since then the constructivist theories are instrumental and bares influence throughout the so-called informal sector of learning. A very good example of constructivist theory of learning in an informal environment is the Investigate Centre at The Natural History Museum in London. Here visitors usually are encouraged to exploit and explore a set of real and natural history specimens, to apply and practice some of the scientific skills and by extension discover for themselves. It mainly employs the scientific learning method of discovery, deductive method.
4.1.2 In Cyprus
In Cyprus there was a considerable proof of using anthropomorphism and animism techniques in science teaching. This practice was across board in all education levels. However, very little is known about the teachers' own opinions on the actual reasons why there was use of animistic and anthropomorphic techniques or on the very issue of whether in science there is need for use of both animism and anthropomorphism. Research information was extracted from recorded interviews and from written tasks. The results did indicate that in the early years teachers appeared to adopt the opinion that animism and anthropomorphism in the past centuries could cause problems of cognitive nature in very young children, and also that the teachers did believe that in extremely special cases the use of animism and cause emotional problems as well. Results also did reveal that teachers used animism and anthropomorphism both consciously and unconsciously and that they attribute their conscious use of these formulations to their low levels of content and pedagogical content knowledge in science.
The earlier science curriculum in U.K and in Cyprus was quite different probably because of their varied intended objects to be achieved. The U.K. mainly employed the discovery method to teach science in schools while in Cyprus, their curriculum mainly used animism and anthropomorphism formulations. In the U.K. the Constructivism learning theory was adopted and still used to date. It had no severe consequences with students unlike the Cyprus curriculum which was unpopular and yet teachers insisted on it. The Cyprus curriculum had adverse effects on young learners' emotion and mind unlike the U.K. curriculum that postulated learning methods which did help learners develop their cognitive abilities. However, the science teaching methods in the two states did cater for the learner's cognitive need.
4.2 Group discussion in the classroom
Learners with varied skills, abilities and backgrounds need to collaborate in performing tasks and discussions so as to arrive at common understanding of the underlying fact and truth in a specified field (Duffy and Jonassen 1992). Nearly all constructivist models like Duffy and Jonassen (1992) also emphasize the necessity for collaboration among students, in direct counter to old competitive approaches which demotivates those who are weak.
4.3 Develop further knowledge in the current views of children about the world
It is better to teach young children by developing their background knowledge in science. Generally, in learning, particularly science learning usually learning occurs in such a scenario the student is taught from known to unknown, from concrete to abstract, from simple to complex and beginning from their background knowledge and further developing that knowledge of their will make learning and teaching science effective, efficient and enjoyable to learners. This approach will also make the learner appreciate what he or she is aware of and retain what they know and most importantly believe in what they know which creates some vital degree of confidence in them. Even those extremely weak or generally slow will to a comfortable level get self-motivated to learn and learn more. They will not see and regard themselves as empty slates in their personal and internal or self evaluation.
5.1 Implications for teaching science
Science learning should be improved constantly and regularly to make it enjoyable and soft to learners. Further and endless research needs to be carried out to improve science learning and help learners to associate imaginations with reality. Such a move will make everyone accept science and will promote the study of science amongst many learners. Proper technique of teaching should be employed by professionally qualified teachers to enable the learner to interact with learning equipment and where possible make discoveries. To make science embraced by majority student populace the teacher needs to employ such methods as collaborative learning so as to aid boost self esteem of dull learners as they are free to interact with their peers and by extension learning equipment.
The study of science can tremendously improve if and when learner's interests and likeness are incorporated into the science curriculum. Such interests should put into considerations learners background, their cognitive as well as motor skills, or generally science learning to be learner centered.