Mr.
Vice Chancellor
Deputy
Vice Chancellor
Registrar
& Other Principal Officers
Dean
of Faculty of Technical and Science Education
Deans
of other faculties and Directors
Fellow
Professors
Staff
and Students
My
Lords Spiritual and Temporal
Distinguished
Scholars
Ladies
and Gentlemen
Introduction
I
taught integrated science, chemistry and biology at various levels of the
secondary school for over seven years in a rural area of
For
over fifteen years of my experience in the tertiary institution, I have been
involved annually in students’ teaching practice supervision. As usual, we
observe how student-teachers learn to teach, point out mistakes and encourage
them to be good practicing teachers. One lesson I learnt these years from
supervising students is that the student-teachers do not believe that the
students they teach have something to offer in science lessons.
Medrano-Asensio (2003) in a workshop of Talent Recruitment and
Public Understanding in Science Education in
He suggested the need to improve pedagogical
methods to teach what science really is.
Mr.
Vice Chancellor, sir, ladies and gentlemen, though world over, performance of
various levels of students has decelerated over the years,
that of Nigerian children is remarkable. Chief Examiners’ reports of
results of our public examinations in the science disciplines are not
encouraging (WAEC,2001 – 2005). Science and scientific
activities are manifested everywhere – in our homes and surrounding, but are
our students getting educated in science?
Mr.
Vice Chancellor, sir, it is customary at the beginning of an inaugural lecture
to say something that is unique in the area one is professing. It is in that
sense that I make claims that this is the first inaugural lecture in the
university in Science Education. The first in the faculty was given by
Professor Tawari in 2002. Professor Tawari’s lecture was the tenth in University Lecture
series, while mine is the seventeenth.
In
the course of my lecture on Science, Science Education and Scientific Literacy,
I shall address the:
(i) nature and structure of science,
(ii) concept of
science education,
(iii) science
curriculum, and
(iv) some issues
associated with teaching and learning science in Nigerian secondary schools.
Nature and Structure of Science
Science is as old as man. The early man
experienced nature as he was able to discover the seasons; when and how to
plant his crops; the necessary conditions for seed germination, the difference
between raw and cooked food and diverse patterns of stability and change of events
in nature.
Longman Dictionary of Contemporary English
describes science as knowledge about the world. STAN (1988) defines science as
a way of looking at and finding out a lot about those things, which occur in
our environment. These concepts of science imply that science is around us. It
is left for us to discover science and provide rational explanations and about
scientific phenomena around us. Various interactions of man with his
environment show that he is sensitive to matter, space and time. He is aware of
uniformity of events in nature. He is often convinced that natural events have
natural causes.
A close look at the nature of science reveals
that science is both deductive and inductive. A deductive science regards the scientific
enterprise as a speculative human activity, which thrives best in an atmosphere
of freedom of thought, creative imagination and intuition. Inductive science
conceives science as a critical and analytical activity in which concrete
evidence precedes a scientific generalization (Medewar,
1969). This is better appreciated when considered with the structure of
science.
Products, methods or processes, and ethics of
science constitute the basic structural components of science. The products of
science deal with scientific facts, concepts, laws and theories. It is through
the use of the products of science that regularities in nature are described,
explained and predicted. Product of science also constitutes the content of
science and refers to “library of knowledge”.
Methods or processes of science relates to
those activities carried out by the scientist during a scientific
investigation. Such activities include observation, classification,
measurement, weighing, counting, prediction, problem identification,
formulating hypothesis, testing hypothesis, experimentation, and interpretation
of data and drawing valid conclusion. The process of science provides the means
of gaining knowledge into the content of science.
Ethics of science provides the code of
conduct of scientists, i.e. his attitudes and behavior, viz;
curiosity, skepticism, objectivity, open-mindedness, humility, honest,
determination etc. Ethics of science also includes strict regulative
principles, viz, careful observation, recording and
reporting of data, using available skills and models, consultations and
discussions at various levels.
The product, process and the ethics are
linked together in a scientific investigation. All science disciplines have
these components of science. For effective and meaningful learning of science,
all the components must be taken into account. How the science teacher handles
the components to a reasonable extent determines the performance of the
students in the science disciplines.
Science begins with observation – observing
with our senses – the eyes, nose, tongue and skin. We observe things in our
environment. We gain some experiences through such observations. Learning
follows from such experiences because learning is a permanent change in
behavior arising from experience, we are told by psychologists.
The Concept of Science Education
Science
education cuts across many fields of human endeavor, namely, the natural
sciences, sociology, philosophy, psychology, history, art, languages, etc.
Science education is not science per se but education in science.
Vice
chancellor, sir, science education is a field of study concerned with producing
a scientifically literate society. It lays foundation for future work in
science and science related fields by acquainting the students with certain basic
knowledge, skills and attitudes. Two other important functions of science
education are:
(a) the training of
science teachers and
(b) The development of adequate science curricula
for the schools (Ogunniyi, 1983)
A
rapidly changing society stimulated by the advances in science demands an
educational programme designed to cope with the
challenge of changes. A society that neither trains its youths about science
nor pays heed to the influences of science on the modern world is doomed to
obsolescence (Hurd, 1964).
Today,
many countries in the world talk about modern technologies, cybernetics and
cyberspace. What is the position of
The
launching of the Russian Sputnik in 1958 raised the revolution that drew the
attention of the world that there was sharp difference between the science that
was learnt in the school and practice of science in the industries and
elsewhere. At this time, some psychological such as Piaget, Skinner, Brunner, Ausubel, Gagne’ and others were preoccupied with how the
children learn. There was the need to reconcile the practice of science inside
and outside the classroom. The science learnt in the schools must be relevant
to the practice of science in the industries and in the society.
Science
Teachers Associations sprang up in the western world with the concern of how
science should be taught meaningfully and effectively. Such associations
influenced teaching of science in African countries and the rest of the world.
Science Teachers Association of Nigeria (STAN) was formed in 1957. One of the
aims of STAN was to promote the spirit of cooperation among science teachers in
The
science teacher must be well equipped if he has to be effective. The science
teacher must not see the students as Tabula rasa (clean state) i.e. the students not knowing anything
at all. But these students are coming from environment rich in scientific
materials and activities that they observe daily. Do the science teachers make
use of the experience brought from home by the students? Despite all the
efforts made by the teachers to improve students’ learning in science, results
at public examinations are still poor.
STAN
(1992) in a position paper outlined a number of factors responsible for the
students’ poor performance in science disciplines. These include the nature of
science curricula, teachers’ methods, the parents, government, and lack of
science facilities in schools amongst others.
Vice
chancellor, sir, in line with these findings by STAN most science education
researchers are working tirelessly in these areas to find out ways of making
our science students learn various science discipline meaningfully. We have concentrated
our research works more in the area of science curriculum, some psychological
factors in learning and problem solving.
The
School Science Curriculum
Curriculum
is the totality of all the experiences provided to a learner under the auspices
of the school. The school science is an integral part of the totality of all
the experiences. Three programmes are clearly defined
for the school science curriculum following from the main school curriculum.
These are programmes of science disciplines, activities
and guidance.
Programme of science disciplines includes physics,
chemistry, biology, integrated science and agricultural science, which are
approved by the Ministry of Education to be taught in the schools. Programme of science activities is a list of activities
arising from the objectives specified for each content
of the programme of science studies. These activities
include what the teacher should be doing in the course of delivering science
instructions in the classroom or the laboratory, and the students’ hands – on
involvement that will enhance meaningful understanding of scientific facts,
theories and laws.
Associated
with the activities are the science process skills. Programme
of guidance has to do with the role of the science teacher as a facilitator of
learning. The teacher, while allowing for the active participation of the
students, also ensures that they are focused in what they are learning. Part of
lathe guidance role of the teacher is to educate the students in science and
science – related careers.
The
Basic Science for Nigeria Secondary Schools (BSNSS), Nigerian Integrated
Science Project (NISP), Nigerian Secondary Schools Science Project (NSSSP) and
National Science Curriculum for senior secondary school are various science
curriculum projects undertaken at the secondary school level and at different
periods of time. STAN, WAEC, NERC (Nigerian Educational Research Council) and
CESAC (Comparative Education Study and Adaptation Centre) were the major
participants in the development of Nigerian Science curricula.
In
addition to the three programmes defined for the
school science curriculum are the latent (hidden) science curriculum and the
extra curricular activities mainly science – related. Hidden curriculum
includes such things, which are not taught in the schools but are brought from
homes and the environment of the learner by the learner to the school.
Students
learn from each other whether good or bad. The role of the teacher is to
encourage the learning of good aspects of the hidden curriculum that will lead
to the realization of the school goals. Part of the hidden curriculum is the
home science. These are scientific activities practiced at homes or elsewhere
outside the school by the learner either consciously or unconsciously.
For
instance, using table salt to give taste to soup, dissolving sugar in water,
boiling beans or rice to soften the protoplasm, allowing the colour of Lipton tea to spread out in the hot water through
diffusion to mention but a few, are all experiences we gain in our homes? One
may ask: are science teachers aware of these experiences? How do they use these
experiences to teach related meaningful lessons?
Home
science experiences are useful and relevant to formal school science. If a good
teacher should teach a lesson beginning from the known to the unknown, a good
starting point is the previous knowledge arising from what the learner knows.
In science teaching, therefore, the teacher can tap from the experiences of the
learners in home science.
Extracurricular
activities, as regards the school science curriculum are those activities that
allow for learning outside the normal classroom bothering on the interest of
the learner. Generally, they include all forms of sporting activities, games,
letter writing, singing, playing musical instruments, excursion, participating
in science clubs etc.
Participation
in science clubs is recommended for science students. In course of students’
participations, they embark on excursions to manufacturing industries, refineries,
production sectors and field trips where scientific activities are observed.
These provide first hand experiences to the students.
Visits to various ecological environments area also fruitful for
the science teacher in driving home his lessons. Sometimes, “seeing is believing”. This saves the teacher from explanations and
afford the students the opportunity of seeing things for themselves. Of
courser, the teacher is there to play his guidance role.
How often do
the science student embark on excursions? Do the
science teacher realize the importance of excursions in science
curriculum? can we not begin to think that students’
poor performance in the school science discipline are linked to the students’
inability to see the relevance of school science to the world of works?
In the
planning of the curriculum, including the integral part, the science curriculum,
student are participants. Apart from being participants, students as learners
are also determinants of what is to be planed. Needs of the
learner as members of the society serve as the main focus in the planning
science syllabuses, which are related to the science disciplines, are part of
the school science curriculum. They are prescribed by the government
according to the needs of her learners and dedicated by the demands of the
Nigerian society as encouraging scientific and technological literacy amongst
the citizenry (FRN,1998).
A
science curriculum deals specifically with the subject matter of science, which
are organized according to the logic of each discipline of science. we shall now discuss briefly, integrated science ,biology,
chemistry and physics curricula.
The philosophy of the integration of science is to
help the child to gain insight into
the concept of the fundamental unity of science, the commonality of approach to
problems of a scientific nature, and an understanding of the role and functions
of scientific nature, and an understanding of the role and functions of science
in the everyday life and the. World in which, he/she lives (Bajah,
1983, Ahiakwo, 1999) Integrated science is studied at the junior secondary
level.
The Nigerian secondary school science
Project (NSSSP) was developed in 1970 by CESAC in biology, chemistry and
physics as an alternative syllabus of WASCE for forms III-v of secondary school
all over the Federation. The objectives of the NSSSP as stated by Ivowi (1981)were to obtain a proper understanding of the basic concept of science,
develop scientific skills especially the manipulative ones and acquire the
right attitude such as honesty, tolerance, objectivity and cooperation. Currently,
biology, chemistry and physics are studied at the senior secondary levels.
Some Issues
Associated with teaching and learning sciences
With the science curriculum
in the hand of the teacher, he is ready to start work. Before a teacher
starts teaching, it may be necessary for
him to find out how the students perceive what he is about to teach them .At
the end of the lesson, the teacher is also encouraged to find out how the student feel about what they have been
taught.
This may help the teacher determine whether the
lesson was too easy or too difficult to learn. If the lesson
was easy to learn the better for the teacher. This saves the teacher the
problem of re-teaching, if the students claimed that they encountered some
difficulties in learning.
The school science syllabuses
contain lists of contents to be taught the students. These are mainly in the
form of examination syllabus converted to teaching syllabus. Examination syllabus is not arranged in
teaching order while the teaching syllabus is arranged in teaching order taking
into account some teaching principles, which include:
(a)
Beginning
from known to unknown;
(b)
Easy
to difficult; and
(c)
Qualitative
to semi-quantitative and to quantitative aspects (Ahiakwo,
1992).
Studies in physics (Onwu and Okpeke, 1985), in biology (Johnstone and Mahmoud, 1980),
agricultural science (Ahiakwo, 1993) and in Chemistry
(Bojczuk, 1982) have been carried out to find out how
students perceive topics in both `O’ level and
`A” level science disciplines. Of particular interest in these studies is the one
conducted in chemistry by Bojczuk.
Bojczuk used British
children in his study and the chemistry syllabus used was the Nuffield `O’ and
`A’ level chemistry. Although there were interesting findings in this study,
Mr. Vice chancellor, sir, it was considered necessary to also find out how the
It was observed that
students perceive difficult to learn such topics as those dealing with ions in
solution, the idea of the mole and its related concepts at `O’ level, while at
the `A’ level, topics related to thermodynamics, kinetics and organic synthesis
pathways (Onwn and Ahiakwo,
1986).
Mr. Vice chancellor, sir, we
are not unmindful of the fact that teach in different school types and classes
of mixed abilities, including the representation of the sexes. Science teachers
assume that students in all school types should be taught sciences the way it
is presented in the syllabus.
A study conducted using
biology students (Ahiakwo, 1995) in mixed and single
schools have shown that arrangement of topics in the syllabus to be taught
should consider the type of school. While for all categories of schools,
agriculture should be taught first to beginning biology students, the study
suggested that for mixed schools,
reproduction, evolution, concept of living, nutrition, ecology,
coordination, genetics, and transport system should follow in that order. For
boys’ schools, evolution, concept of living, nutrition , ecology,
transport systems, reproduction,
genetics and coordination; and for girls’ school reproduction, concept of
living, coordination , ecology , evolution , genetics , nutrition and
transport system should be taught in that order.
What is being taught to the students must be
relevant to their development at that particular time. While not advocating
gender disparity in the learning of science, everything should be done to
encourage the learner irrespective of gender.
Mr. Vice chancellor, sir,
one dimension of students’ perception of the science disciplines, which has
been exhaustively worked on by researchers outside Nigeria is that which
unravels students’ “Image of science and
scientists”(Kahle’1987;Shebecci,1986;Shebecci and
Sorensen,1983;Weinreich-Haste,1981;Krajkovich and smith,1982,Rae,1982;Rennie,1986).Finding
of these studies have implications, generally, is the correct knowledge of the
people who do science.
For example, science has
been seen as involving magic, white man’s lies(Bajah,1988).``scientist are
magicians, sorcerers, mad people and unkempt people who just stay in secluded
places and be thinking and mixing all sorts of things” Specifically, senior
secondary chemistry student from Port Harcourt metropolis were requested to
draw a chemist. Their drawings showed a chemist as a man having facial hairs,
wearing eye glasses or goggle and wearing laboratory coat with pens and pinned
in his left top pocket and using laboratory materials and equipment to mix all
sorts of things (Ahiakwo,2000).
These impressions, if not
corrected, are capable of affecting how student study sciences. besides, the type science taught by the teachers and learnt
by their students may be close to what may be describe as ``bucket science (Gordon,1984)or pop``.
science”(Basalla,1976)different from popular science, which relates to the
actual practice of the science community(Schebeci,1986).
Over the
years ,there have being various programmes put in
places to popularize science (Bajah,1988).Both sexes are encouraged to enroll
in science and science related careers,
though students have continuously seen the science disciplines from different
perspectives.
Biology is considered
as soft science and embraced more by the girls, while physics is seen as a hard
science and have boys enroll more in
it(Bajah,1988).Chemistry is seen as moderate science between biology and
physics are difficult subject to learn. Records exist that secondary student’s
performance in science disciplines is poor(Ahiakwo,1992,1994;Ogunleye,1999).
Mr. Vice Chancellor,
sir our research has taken us into probing the difficulties students have with
learning some of these specific topics with the view of helping them.
For instance, in chemistry,
especially the topic in electrochemistry having to do with ionic equations,
students are unable to conceptualize the movement of ions in solution. We prescribe
the use of descriptive approach first before applying technicality. Given an
equation: Cu(s) Cu2+(aq) + 2e- , we suggest that teachers can
simply say that “a copper atom loses two electrons to become copper ion in an aqueous solution of the salt
of copper(say copper II tetraoxosulphate VI, CuSO4)(Ahiakwo,1989)This
equation allows to be written as cu(s)-2e. Cu for meaningful qualitative understanding,
noting with caution that the two electrons are not physically plucked off the
copper metal atom.
One other
concept student have difficulty in understanding is aromaticity
as demonstrated with the pi () electrons of the benzene ring. The concern of a
chemistry teacher is ensuring student’s understanding of aromaticity
is that many derivatives of benzene stem from the thorough understanding of the
concept. Students do not understand why the canonical structure s of benzene
should be represented by a single structure. His misunderstanding stems from
the lack of understanding of the resonance behavior of the pi electrons.
Although models are used to explain this to students, we still encourage in addition,
verbal description to improve student’s understanding (Ahiakwo,
1998).
A science
educator is always ready to help practicing teacher develop strategies for teaching
various science topics.Steategies have been developed
for such topics as erosion and acid rain, controlling of the environment,
chemical aspects of water pollution, mole concept and equilibrium (Ahiakwo,1995;1999;2000).
Mr. Vice Chancellor,
sir, the problem of language is not solved yet in science teaching and
learning. Our students have to understand, speak and write English language
before they could learn science. There was this Bulgarian chemistry lecturer
who once told us that she could teach chemistry in English because she prepared
her lessons using her Bulgarian chemistry books written in Bulgarian language.
In secondary
school, we were once taught physics by an Indian teacher who could not
communicate in English language but used sign language. Language is very
important in passing instructions to learners. Effective communication while
also make the learner learn better and faster.
One of my masters students carried out a study to find out the
effectiveness of the use of Ogba language in teaching
primary science in the primary schools. A group of primary six pupils received
science instruction in Ogba, and English language
while another group received instructions in English language only. The group
that was thought in Ogba and English language
performed significantly better than the group thought only with English
language (Wokocha, 2002). The conclusion was that the
use of once own language assist in learning science.
In my view,
although Wokocha’s study was with primary school
children, the finding gives a picture of what we should expect using secondary
school students tongue in teaching in our schools, but sufficient attention has
not been given to this suggestion
One of the
problems, to my mind, is the definition of one’s mother tongue –Is it your
dialect or the language of your immediate environment? The use of mother tongue
will need further clarification; however, it is not the focus of the lecture.
The lesson that is clear is that the use of one’s language with English
language will facilitate sciences learning.
Young learners,
apart from assisting them to learn with language, also need external memory
aids. In my opinion, this could help reduce examination malpractice in science
and science related courses, which has been a major concern in the educational
sector. Students want to cheat to pass examination. If, they (students) are
properly taught, there is the likelihood of their facing examinations with
confidence, without turning their necks to see what another student is writing
or going into the hall with illegal materials that will assist them supposedly.
Studies have
shown that the use of external memory aids assist science learning. External
memory aids are gadgets or materials outside the memory of the learner that
will assist the learner in the recall of needed scientific information or
calculations. These include the supply
of mathematical formulae, constants, facts and the use of calculators or
computers.
Ahiakwo (2000) carried out a study
using senior secondary students to find out the effect of the use of
calculators in the performance of students in quantitative chemistry. The study
revealed that students who carried out their computations with calculator perform
better than students who were merely required to depend on their memory alone.
The study showed that the use of such external memory aid is helpful in
learning quantitative aspect of chemistry. There is also no doubt that such
memory aid will be useful in other science disciplines. This means that for the
students to learn mathematical aspect of science, they need calculators. One is
tempted to ask: How many of the students
can afford calculators? Will it be too
much for the school to provide calculators to all students who are studying the
science disciplines and science related disciplines? I believe that something can be done as a way
of encouraging the students who are interested in learning science in our
schools.
Mr. Vice
chancellor, sir, distinguished ladies and gentlemen, one of the factors that
bother the science educators is the commitment of the students to science
learning. How do students learn science? How do students behave when they are
faced with scientific tasks? How do they respond to scientific
information? These questions are better
answered when we consider students’ preferences to scientific information and
their behavioural styles of tackling scientific
tasks.
Students’ Cognitive Preferences and Cognitive Styles in Science
learning.
Science students
should be able to recall ideas and facts from memory and distinguish principles
from applications through critical questioning. These from basics of students‘
preferential behaviors in responding to scientific statements (Health,
1964). Cognitive preferences have been transformed into a test, which
demonstrates the overt behaviors of students in scientific statements
especially those related to recall of information, principles, application and
critical questioning (Oyedum, 1982).
This type of
test has been used in determining students’ cognitive preferences in physics (Ogunyemi and Eboda, 1974);
chemistry (Hofstein et. al.1978; Shuaibu
and Ogunsola, 1983);biology
(Amir and Kempa, 1978);
mathematics (Ogunyemi and Bettie, 1974). There was
the need to find out students’ cognitive preferences in integrated science,
which enable individual to solve problems in science no matter the discipline.
Ahiakwo (1999) conducted a study to
determine the cognitive preferences of junior and senior secondary students in
integrated science. The study revealed
that many students were found responding to the preference test on recall
answers than the other preferences. There was a general decrease in response
preference from recall through principle to application for all the students.
Many students being at the recall level do not make room for inquiry and
inquisitiveness required in learning science. Learning science requires also
questioning and using principles to make description and explanations. Where
the students’ preference for scientific information is limited to recall from
their memory, this gives room for rote learning in places of meaningful
learning.
The main idea in
determining the cognitive preferences of students is to help the science
teacher on how to present science lessons to the students. This can also help
the science teacher in upgrading the preferential levels of the students. For example , a teacher can upgrade students’ level from recall
to the use of questioning to problem solving status (Ahiakwo,
1991).
One problem with
the use of cognitive preference test is that it depends on the discipline. Cognitive preference in physics is different
from that in biology. It is content-dependent. It takes some expertise in
preparing cognitive preference Test, which most science teachers are not
disposed to. One would think that some science teachers do not consider the
cognitive preference of their students before teaching them. Since most of the
science students are operating at the recall level, it becomes convincing that
instructions to the students are mainly at the recall level. We can see that
our students are not learning science meaningfully. This explains why most of
our students cannot cope beyond the senior secondary level where abstract
scientific learning takes place. We will need to reconsider our teacher
education. Specifically, our pedagogical content knowledge for the teachers in
training will need fine tuning to include teachers ability to determine the
science cognitive preferences of their students before teaching them. Since
most of the science students are operating at recall level, it becomes
convincing that instructions to the students are mainly at the recall level. We
can see that our students are not learning science meaningfully. This explains
why most of our students can not cope beyond the secondary school level where
abstract scientific learning takes place. We need to reconsider our teacher
education curriculum in the university and colleges of education. Specifically,
our pedagogical content knowledge for the teachers in training will need fine
tuning to include teachers ability to determine the science cognitive
preference of their student before teaching them.
The concept of cognitive
style is simply associated with and arises from the area of psychology know as
psychological differentiation. By this is meant that differences exist between
different individuals in relation to their psychological functioning and where
such psychological functioning appear to take place in stable or relatively stable
modes, certain characteristics (styles)may be ascribed to it (Witkin, et.al., 1977).Cognitive
style refers to an individual’s way of perceiving and processing information.
In short, the way the individual learns.
There is different type of cognitive
styles but the one of interest is the categorization styles. There are three
types of the categorization styles, viz, the categorical
inferential (CI), Analytic-descriptive (AD)and the
Relational contextual (RC) (Sigel,1967,Kegan et.al.,1963).These styles modes
are better understood when the students are presented with a set of three pictures.
For example, a set of picture containing a standing man, a watch and a ruler,
if a student is asked to collect any two pictures and say something about them,
CI student could say that “the watch and the ruler are measuring instruments”.
This statement indicates the tendency to group together objects or events on
the basis of super ordinate features, which are not directly discernable, but
are inferred. A student categorized as AD may say that “a watch and ruler are
placed together because they have numbers”. AD style students have the tendency
of grouping together objects or events on the basis of common characteristics,
which are directly discernible.
The RC style is
the tendency to group together objects or events on the basis of feature
establishing a relational link between them. For example, a
relational-contextual style students may place together and the watch on the
ground that “the man can wear the watch”
In most studies
CI and the AD are lumped together and called Analytical style
(NS)(Gardner,1953;Onyejiaku,1980;Mansary,1985).his is because of the nature of
statements, which are obtained from the respondents to the categorization style
Test (CST).Unlike the cognitive preference Test (CPT),the categorization style
test (CST)is not content dependent. While the respondents cued in the cognitive
preference test (CPT), the categorization style test (CST)is
not content dependent. While the respondent is cued in the cognitive preference
Test, he is free to make any statement based on the observed picture in CST.
Science carried out
reasonable studies to un education researchers have carried
out reasonable studies to unravel how two categories of students-Analytic and
on-analytic, tackle scientific tasks. Ahiakwo (1991) investigated
how these two groups of students solve quantitative problems in electrochemistry.
Though the study made this revolution, on close examination of the script of
the students used for the study are insights into how they approach the
problems.
Problem-Solving
in Science
Problem –solving
is bridging the gap between a problem and a solution by using information
(knowledge) and reasoning. A problem exists when there is no immediate solution
or answer. Frazer (1982) has defined two common types of problems encountered
in science. These are the open and close-ended problems.
In open problems,
solutions are not known while in the close-ended problems, the solution, are known.
Close-ended problems are commonly encountered in the science disciplines. Understanding
how individual students attempt close-ended problems in science helps the
teacher in detecting where mistakes are made and also give the teacher some new
clues in improving on science instructions science teacher would need to put
himself in the position of the students (woods, 1978).
A better way of
understanding how students solve problems is by examining the solution offered
by them to a given problem vis`a-visa
a problem-solving model. Many problem –solving models exist see (Ahiakwo, 2000).The one that appears to be commonly used in
investigating the problem-solving behavior of student is the Ashmore et.al`s (1979) model.
This is because the model could be used to investigate qualitative, semi-quantitative
and quantitative problems. It also allows a network to be developed concerning
the reasoning patterns of the problem-solver.
Ashmore et.al`s model have five stages,viz
(i)ability
to define the problem;
(ii)select
information from the data or problem-statement;
(iii)recall information
from the memory;
(iv)computation
leading to the solution of the problem.
The model can be made cyclic
because there is room for evaluating the solution obtained by looking back as
in fig.I.
Fig.1.Cyclic
Model of Ashmore et al’s Problem-solving Model.
When the student solutions to the
six quantitative problems were subjected to the model, two patterns emerged
typical of what the student do in the classroom (Ahiakwo
and Onwu,1996).The Analytical style students were
observed to have followed a step-by-step strategy in arriving at the solution
while the non-analytic style students did what we describe as “routine
operation”, thus, problem-solving network analyses are presented in
Fig.II and III.
Fig. II Step-by-step
Operation Fig. III Routine Operation
Key:
□
- Information from
problem-statement.
à
- Information from memory
o - Reasoning
using information from memory and problem-statement.
-
Solution
We see that in
the figures representing network analysis, the analytic style students (fig.
II) tend to solve their problem following the step-by-step stages as defined in
the model. It could be taken that the students considered every detail or
information while attempting the problem. Fig. III represents the network
derived from the solutions of non-analytic style students. This depicts a
solution where the students put all the information together to obtain the
solution of the problem.
Mr. Vice chancellor, sir, a non-analytic problem – solver will be
favoured by a teacher who is only interested in the
answer of the problem. He will not be favoured by a
teacher who insists on showing “all working” to a problem.
On the other
hand, a teacher interested in detailed working will favour
an analytic problem – solver. This is the dilemma of science teachers, when it
comes to evaluating the students work in semi-quantitative questions. Even when
instruction insists that the student should show “all working”, what constitutes
“all working” is only determined by the teacher’s marking scheme. Is it not
possible for the teacher to keep aside his marking scheme and carefully look at
how student solve science problems in the classroom? It is possible for a
devoted teacher to carefully consider each student’s script and pattern
followed in arriving at the solution of a problem. By doing this, the teacher
might be helping both the analytic problem – solver.
Individual difference in learning has long been recognized as a
factor that could affect group learning. This is the reason why teacher are
advised to allow the students to learn at their own pace. It may take a short
time for some students to attain their goals while for others, it may take
longer time. Science education researchers are also interested in how the
teacher can help the students attain their individual goals in science lessons.
Advance
organization and concept Mapping in science Learning
The concept of advance
organizer is that of David Ausubel Ausubel (1969)posited that instructional sequence should
begin with a set of broad but comprehensive statement at a higher level of
abstraction to what it is to be learnt. He
calls such statement “Advanced Organizers”. These organizing statement are used
to link the new materials with what the learner has learnt already i.e. his
cognitive structure. This can be represented, thus:
Fig.IV: Scheme of “Advance
Organizer” learning
Urevbu (1990) remarked that a
function of the organizer is to increase recall. Apart from that, the use of
Advance organizer is called for, under two circumstances. The first is when the
student has no relevant information to which he can relate the new learning.
The second is when is when relevant subsuming information I already present but
is not likely to be recognized as relevant by the learner (Ausubel,
1963).These functions provide the basis for distinguishing lesson planned on advanced
organizer and the conventional plan carried out by teachers. Ahiakwo and Iwuoha (1999) carried
out a study to find out the effect of advance organizer on students’
performance in some aspect of biology. It was found that students exposed to
instructions based on advanced organizer performed better than the student who
were not exposed to instruction based on advance organizer. It was concluded in
that study that since the use of instruction based on advance organizer has
shown its efficacy on the performance of the student in biology and other
science discipline (kohl and Rastovac, 1976)teachers should be conversant with it.
We also observed
that teachers are not interested in such development .Teachers are not aware,
most of the teachers do not attend conferences, workshops and seminars where
the utilization of such of such concept in teaching is discussed. Teachers do
not make use of this important concept in teaching sciences lessons.
Close to the advanced organizer is the use
of concept-mapping teaching technique in teaching science in schools. A concept
map is a schematic device for representing a set of concept meanings embedded
in a framework of proposition (Novak and Gowin,1984).
This could be in the form of diagrams indicating inter-relationships among
concept as representation of meaning or ideational frameworks specific to
domain of knowledge (Novak 1990). Some studies (Okebukola
and Jegede, 1989; Pankratius,
1990; Udeani, 2000; Markov and Lonning,
1998) have reported the efficacy of concept mapping strategy in terms of
improving the performance of students in various aspects of the various
disciplines. These notwithstanding, more studies are needed especially when we
are dealing with different students in different locations with different
backgrounds.
Ahiakwo and Osiago
(In press) carried out a study, which sought to find out the effect of concept
mapping on the performance of senior secondary biology students in genetics.
Five lessons based on students’ concept mapping on genetics were prepared and
taught to a group of students for a period of three weeks. Another equal group
received instructions on genetics but not concept-mapping-based. Group of
students who were taught with concept mapping performed better than the
students who were not exposed to concept mapping. The study proved that the
experience of the student should be considered while preparing learning
materials for them, otherwise the teacher would end up teaching himself or
herself.
This is really the need to emphasize the consideration of the
knowledge of the students in science lessons. This will require the skill of probing
the cognition of the students for information.
Constructivism
and Science teaching
It has been mentioned earlier that the children we have in our
classroom bring with them experiences from homes, from their communities, from
peers and from their environment. These experiences have scientific content
useful as springboard for the teacher to progress in science lessons. Students’
experiences contain science process skills necessary for the understanding of
the formal school science process skills. The clinical technique is used to
probe into the memory of the students to know what is there concerning
scientific information.
The student is made to verbalize aloud what is there in his
memory. Students’ verbalization is tape-recorded. This is referred to as
protocol, which is later transcribed and analyzed (protocol analysis). Although
paper-and-pencil can be used to obtain information from the student but it is
not as effective as the protocol information. In paper-and-pencil, the student
may not be able to write down everything he has to say about an issue in his
memory.
Onwu (1981) was able to use the
clinical technique to probe the difficulties, which the British children have
with learning the mole concept in chemistry. Alamina
(2000) studied understanding of concept of combustion and precipitation among
British children. The finings of these two studies actually show that we can
assess and use information contained in individual’s memory is also useful in
assessing and ascertain the individuals’ mental or memory capacity. By knowing
this, we can plan how to “feed” the student so that we do not “underfeed” and
we do not “overfeed” him.
In a nutshell, it enables science teachers to know what to teach
for a given time that will allow for mastery learning. In all, constructivism
has to do with finding out the student’s idea about a scientific concept. In
these sense, we talk about the student’s construct and using such construct to
teach him or her.
Currently, we have students at the postgraduate level who are
involved in constructivism research in science education. While, making some of
the students to think aloud, we were able to draw a list of experiences likely
to be recalled by students that will help the teacher in teaching some
scientific concepts (see Table 1).
Table1: School
Science Concepts and Home Science Concepts
|
School
Science Concepts |
Home Science Experiences |
|
Floatation/buoyancy |
Canoe on water, floating plastics/materials. |
|
Fermentation |
Sweet palm wine left for days, Cassava soaked in water. |
|
Force |
Pushing wheelbarrow, Carrying Jerrycan of water on head, lifting
objects |
|
Vaporization/boiling |
Cooking with pot that is steaming, steam coming
out from boiling pot. |
|
Diffusion |
A cup containing hot w |