EFFECTS OF ADVANCE ORGANIZER TEACHING APPROACH ON SECONDARY SCHOOL
Transcript of EFFECTS OF ADVANCE ORGANIZER TEACHING APPROACH ON SECONDARY SCHOOL
International Journal of Social Science & Interdisciplinary Research__________________________________ ISSN 2277 3630 IJSSIR, Vol. 2 (6), JUNE (2013) Online available at indianresearchjournals.com
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EFFECTS OF ADVANCE ORGANIZER TEACHING APPROACH
ON SECONDARY SCHOOL STUDENTS’
ACHIEVEMENT IN CHEMISTRY IN MAARA DISTRICT, KENYA
PROFESSOR SAMUEL W. WACHANGA*;
ANTONY MUGIIRA ARIMBA**;
PROF. ZACHARIAH K. MBUGUA***
* DEAN FACULTY OF EDUCATION AND COMMUNITY STUDIES
EGERTON UNIVERSITY, KENYA
**FACULTY OF EDUCATION
CHUKA UNIVERSITY, KENYA
***FACULTY OF EDUCATION
KARATINA UNIVERSITY, KENYA.
______________________________________________________________________________
ABSTRACT
Students‟ achievement in Kenya Certificate of Secondary Education (KCSE) Chemistry
examinations in Kenya is below average. This could be due to among other factors, the teaching
methods used by teachers. There is need for teachers to use teaching methods that can enhance
students‟ academic achievement in Chemistry in secondary schools. This study investigated the
effects of Advance Organizer Teaching Approach on students‟ achievement in Chemistry. Quasi
–experimental research was employed since intact chemistry classes were involved. This was
because school authorities do not allow classes to be broken and reconstituted for research
purposes. Solomon‟s Four Non-Equivalent Control Group Design was used. The study involved
secondary schools in Maara District, Kenya. The target population was 13,036 secondary school
students while the accessible population was 3,540 Form Three chemistry students. Purposive
sampling was used to select four district co-educational secondary schools in Maara District. The
sample size involved 161 Form Three chemistry students who were in four groups E1, E2, C1
and C2. Chemistry Achievement Test (CAT) was used for data collection. The CAT was
administered to groups E1 and C1 before teaching started. The experimental groups were taught
using the Advance Organizer Teaching Approach (AOTA) while the control groups were taught
through Regular Teaching Methods (RTM). The CAT was pilot tested to determine its reliability,
while its validity was ascertained by experts from Department of Education of Chuka University
College. At the end of eight weeks of teaching the CAT post-test was administered to the four
groups. Statistical package for social sciences (SPSS) was used for data analysis. Descriptive
statistics (mean, percentages, and standard deviation) and inferential statistics (ANOVA,
ANCOVA, and t- test) were used for data analysis at α= 0.05 level. The study found out that
there were significant effects of the use of advance organizers in Chemistry learning. Students
who were taught using AOTA achieved better in Chemistry learning than those who were taught
through RTM. The findings of this study also indicate that gender has no significant effects on
CAT scores in Chemistry learning when AOTA is used. Based on this study teachers and
curriculum developers should adopt and strengthen the use of advance organizers as a teaching
strategy to enhance Chemistry learning by students.
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KEYWORDS: Advance Organizer Teaching Approach, Chemistry Achievement Test, Regular
Teaching Method, students‟ chemistry achievement.
Introduction
Chemistry is the science that underpins most of the major discoveries of the 20th century and
still will continue to do so in the 21st century as emphasis moves towards the understanding of
biological approaches and more eco-friendly synthetic systems such as forensic chemistry,
environmental, soil and water chemistry (Webster, 2009). Chemistry courses have low rates of
student success and as a result serve as a gate-way limiting access to science fields (Webster,
2009). Students learn best when they possess an integrated package of skills and beliefs that
support learning.
Cognitive psychologists believe that all of a person‟s prior knowledge is stored in the cognitive
structures of the brain. Ausubel (1960) determined through extensive research that “the most”
dependable way of facilitating retention is to introduce the appropriate subsumers and make
them part of cognitive structure prior to the actual representation of the learning task. The
introduced subsumers thus become advance organizers or anchoring foci for the reception of new
material (Ausubel, 1960). Bransford (2004) and Anderson (2004) agree with Ausubel that
advance organizers are an excellent way to activate and build schema prior to the actual learning
of new material by students. Based on the initial response to the material presented in the
organizer, teachers can modify their lesson plans and materials to better fit the prior knowledge
of their students. In addition, they can efficiently structure their time and the critical points that
need to be covered, while simplifying complicated text Bransford (2004) & Anderson, (2004).
This enhances the development of higher order thinking in their students by helping them to
relate concepts previously learned to the new material and enabling them to quickly organize
their thoughts.
Despite many researches that have been done in the efforts to improve achievement in sciences
in secondary schools, performance in Chemistry continues to be poor. Kenya‟s Ministry of
Higher Education Science and Technology (MoHEST) has made several efforts to address the
causes of poor performance in chemistry. For example, the training of chemistry teachers has
been enhanced so as to have trained teachers in all schools. However, the problem of poor
performance in chemistry persists. Emphasis should be among others on the use of innovative
teaching strategies such as the use of advance organizers.
An advance organizer is a statement of inclusive concepts to introduce and sum up material that
follows (Woolfolk, 2001). Ausubel (1960) defines an advance organizer as a cognitive
instructional strategy used to promote the learning and retention of new information. An advance
organizer is information that is presented prior to learning that can be used by the learner to
organize and interpret new incoming material (Mayer, 2003).
In explaining the meaningful learning, Ausubel (1960) introduced the concept of a subsumption
model as a pedagogic device in which central and highly unifying ideas are stated in terms
already familiar to the learner, to which the learner can relate new ideas by subsumption. A
primary process in learning is subsumption in which new material is related to new and relevant
ideas in the existing cognitive structures (Adebola, 2011). The organizer is introduced in advance
of learning itself, and is also presented at a higher level of abstraction (Ausubel, 1960). A few
have been conducted on the effects of advance organizers in learning and learners performance
(Adebola, 2011). For example, Githua and Nyabwa (2007) found out that students taught using
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advance organizers had significantly higher scores in mathematics achievement test than those
taught in the conventional way. According to Harg and Willerman (1991) students can probably
be helped by the organization and visual relationships of the advance organizer in a way that oral
explanations do not offer. Wachanga and Mwangi (2004) explain that successful teaching and
learning depends partly on the correct use of a teaching method whose activities target most
learning senses.
Chemistry is poorly performed in national examinations and in particular Maara District (KNEC;
2008; 2009). In the present study, teaching of chemistry was done through the advance organizer
approach in order to find out whether students‟ achievement would be affected positively.
Purpose of the Study The purpose of this study was to determine the effect of using Advance Organizer Teaching
Approach on secondary school students‟ achievement in Chemistry in Maara District.
Objectives of the Study In order to achieve the stated purpose, the following objectives were used to guide the study.
i. To determine whether the achievement of students who are taught through Advance
Organizer Teaching Approach (AOTA)would be different from that of those taught using the
Regular Teaching Method (RTM).
ii. To determine whether students‟ achievement was affected by gender when they are
taught through Advance Organizer Teaching Approach.
Hypotheses The following hypotheses were tested at α=0.05 level of significance.
HO 1: There is no statistically significant difference in achievement scores in
Chemistry between students who are taught using AOTA and those who are taught using RTM.
HO 2: There is no statistically significant difference in achievement in Chemistry between boys
and girls who are taught using AOTA.
Conceptual Framework
In this study advance organizers were used as an intervention in the teaching of the Mole concept
topic in Chemisty. The interrelated variables are shown in Figure 1.
Independent Variables
Intervening Variables Dependent Variable
Advance Organizer
Teaching Approach
(AOTA)
Regular Teaching
Methods (RTM)
Teacher characteristics
-Gender
-Experience
-Training
Learner characteristics
-Age
-Gender
Students‟
achievement in
Chemistry
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Figure 1: Interrelationships of variables in the study.
The intervening variables were classroom environment, learner and teacher characteristics. To
control for teacher variables, the study involved female trained teachers with at least 3 years
teaching experience in Chemistry at secondary schools level. The effect of students‟ age was
controlled by involving Form Three chemistry students who are approximately the same age.
Effect of students‟ gender was incorporated in the study.
Research Methodology
This study involved quasi-experimental research in which the Solomon‟s Four Non-Equivalent
Control Group Design was used. It was not possible to randomly assign students to groups as
they exist in school as intact groups (Wachanga & Mwangi, 2004). The Solomon„s Four Non-
equivalent Control Group Design is presented in Figure 2.
E1 O1 X O2
----------------------------------------------------------
C1 O3 _ O4
----------------------------------------------------------
E2 _ X O5
----------------------------------------------------------
C2 _ _ O6
Figure 2: The Solomon„s Four Non-Equivalent Control Group Design
O1 and O3 were pre-tests while O2, O4, O5 and O6 were post-tests and X was the treatment
where students were taught using Advance Organizer Teaching Approach in the Mole Concept
topic in Chemistry. E1 was the experimental group which received pre-test, treatment and a post-
test. C1 was true control group which received the pre-test followed by the control condition and
the post-test. E2 was the experimental group two which received treatment followed by the post-
test. C2 received the control condition followed by the post-test. C1 and C2 were taught using
Regular Teaching Methods.
Maturation and history effects were controlled in this design by having two groups taking a pre-
test and a post-test (Fraenkel &Wallen, 2000). To avoid the effects of contamination, the
treatment and control groups were from different schools which were far apart. Pre-test enabled
the researchers to check the entry level of the students before the experiment started.
Sampling Procedure
Purposive sampling was used to identify the schools with the desired characteristics from the list
of schools in Maara District. The desired features of the schools that qualified for the study were:
a class size of more than thirty Form Three chemistry students, female chemistry teachers, well
equipped chemistry laboratory and district co-educational secondary schools. Group E1 was
from Mwimbi Division while Group E2 was from Muthambi Division. The control groups were
from Mwimbi Division and at an approximate distance of eight kilometers apart. These two
divisions belong to Maara District. From the sampled schools, simple random sampling method
was used to obtain four classes and assigning them to experimental and control groups.
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Sample Size
According to Mugenda and Mugenda (2003) at least 30 cases are required in each group for
experimental research. In this study the number of students in the sample size was 161. The
number of students in E1 were 49, C1 were 41 while in E2 and C2 were 36 and 35 respectively.
The total number of students was 161. Table 1 shows the summary of the sample size indicating
the number of the students in the four groups.
Table 1
Summary of the Sample Size
Group
Number of Students
Experimental one (E1) 49
Control one (C1) 41
Experimental two (E2) 36
Control two (C2) 35
Total 161
Instrumentation and Data Collection
The Chemistry Achievement Test (CAT) was used to measure students‟ achievement in the Mole
Concept topic of Chemistry. This test consisted of items that were covered in Mole Concept
during the eight weeks of study. The content tested involved the mole, relative atomic and
molecular masses, empirical and molecular formulae, molar solutions, chemical equations,
titration and molar gas volume. The test contained 10 items having a total score of 25 marks. The
items tested knowledge, comprehension, application and analysis of chemical information. Two
experts from Chuka University in the Department of Education and two examiners from Kenya
National Examinations Council (KNEC) assisted the researchers to ascertain the validity of the
test and also to review the test. Pilot testing was done in Embu East District in a co-educational
district secondary school which had similar characteristics as the sampled schools. The data that
were obtained from piloting assisted the researchers to determine the reliability of the test. The
reliability co-efficient was calculated using the Cronbach‟s alpha method because the items
yielded a range of scores. The test had a reliability coefficient of 0.83. This value was above the
threshold of 0.7. Thus the test was considered to be suitable (Fraenkel & Wallen, 2000). The
test was administered at the beginning of the study as a pre-test. At the end of the eight weeks of
study the items of the pre-test were reorganized to serve as the post-test.
Data Analysis
Descriptive statistics (mean, standard deviation, percentages) and inferential statistics (ANOVA,
ANCOVA and t-test) were used for data analysis. The one-way ANOVA was used to analyze
differences in the four means. It was used to establish whether there were significant differences
among the mean scores of four groups. In order to take care of any initial differences among the
groups, an Analysis of Covariance (ANCOVA) was carried out using KCPE marks as the
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covariate in all the four groups (Thorne & Giesen, 2000). Independent samples t-test was used to
test if there was a statistically significant difference between two mean scores of experimental
and control groups (Mutai, 2000).This is because of its superior power to detect differences
between two means (Borg & Gall, 1989). The level of significance for acceptance or rejection of
null hypotheses was set at α= 0.05.
Results and Discussion
The independent samples t-test was used to analyze whether there were significant differences in
the mean scores of experimental group (E1) and the control group (C1) in the CAT pre-test.
Data in Table 2 shows the t-test results of the pre-test mean scores in CAT for E1 and C1.
Table 2
t-Test Results of the Pre-test Mean Scores on CAT
Group N Mean score (%) SD df t-value p-value
E1 47 20.94 17.10 77 0.65 0.52
C1 32 18.25 19.38
Total 79
E1 had a higher mean score (20.94%) than C1 (18.25%). However, the difference was not
significant t (77) = 0.65, p>0.05. Independent samples t-test was used to analyze whether there
was significant differences between the mean scores of boys and girls in CAT. Data on Table 3
shows the results in CAT based on gender.
Table 3
t- Test Results of the Pre- test Mean Scores on CAT by Gender
Gender N Mean Score (%) SD df t-value p- value
Male 30 15.87 18.54 77 -1.55 0.12
Female 49 22.29 17.38
Total 79
The results indicate that girls had higher mean scores (22.29%) as compared to boys (15.87%).
However, this difference was not significant t (77) = -1.55, p>0.05. Results in Tables 2 and 3
shows that the groups were similar at the beginning of the experiment.
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Effects of AOTA on students’ Achievement in Chemistry
One way ANOVA was performed to analyze whether there was any significant difference in
achievement scores of students taught using AOTA and those taught using RTM. The results of
the students CAT post-test scores were as shown in Table 4.
Table 4
CAT Post-test Mean Scores Obtained by Students in the Four Groups
Group N Mean Score (%) SD
E1 49 30.37 18.30
C1 41 21.85 14.20
E2 36 31.72 16.04
C2 35 22.74 13.84
Total 161 26.84 16.34
The mean scores of the E1 (30.37%) and E2 (31.72%) were higher as compared with those of the
C1 (21.85%) and C2 (22.74%). This shows that experimental groups achieved better than the
control groups. This study found out that students taught using AOTA achieved better in CAT as
compared to those students taught using RTM. This indicates that the use of advance organizers
enhanced learners to learn Chemistry.
The CAT mean scores for the four groups are shown in Figure 3.
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Figure 3: Relationships between Post-test Mean Scores in CAT in the Four Groups
Analysis of Variance (ANOVA) of the post-test mean scores in CAT are shown in Table 5
Table 5
Analysis of Variance (ANOVA) of the Post-test Mean Scores on CAT
Sum of Squares df Mean Square F p-value
Between Groups 3074.70 3 1024.90 4.06 0.01
Within Groups 39658.42 157 252.60
Total 42733.13 160
The results in Table 5 show that the differences between the post-test scores on CAT were
statistically significant F (3, 157) = 4.06, p< 0.05.
Least Significant Difference (LSD) Post Hoc comparisons were carried out to establish the mean
scores which were statistically different. The results are shown in Table 6.
Table 6
Post Hoc Comparisons of Post-test of CAT Mean Scores for the Four Groups
Group Group Name Mean difference Standard error Significance
Name
(i) (j) (i-j) p- value
E1 C1 8.51 3.36 0.01*
C2 7.62 3.52 0.03*
E2 -1.35 3.45 0.70
C1 E1 -8.51 3.36 0.01*
C2 -0.89 3.66 0.81
E2 -9.87 3.63 0.01*
E2 E1 1.35 3.49 0.70
C1 9.87 3.63 0.01*
C2 8.98 3.77 0.02*
C2 E1 -7.62 3.52 0.03*
C1 0.89 3.66 0.81
E2 -8.98 3.77 0.02*
* denotes that the mean differences are significant at 0.05 confidence level.
The results indicate that the differences in mean scores of groups E1 and C1, groups E1 and C2,
C2 and E1, C2 and E2, E2 and C1 were statistically significant at 0.05 level and therefore H01 is
rejected. Since the study was quasi experimental, the researchers carried out Analysis of
Covariance (ANCOVA) using KCPE scores as covariates. The results in Table 7 show the
adjusted mean scores for ANCOVA.
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Table 7
Adjusted Mean Scores of the Four Groups
Group N Adjusted Mean Scores (%
E1 49 30.51
C1 41 22.30
E2 36 23.24
C2 35 31.10
Total 161 26.84
Table 8 shows the results of ANCOVA.
Table 8
Analysis of Covariance (ANCOVA) of the Post- test Mean Scores on CAT using KCPE marks
as the Covariates
Source Sum of Squares df Mean Square F sig
KCPE 176.64 1 176.64 0.69 0.41
Group 39481.18 156 253.01 4.28 0.01
Error 3251.32 3 1083.78
Total 158750 161
Corrected Total 42733.12 160
The ANCOVA results indicate that the differences are statistically significant since p<0.05.
Least Significant Difference (LSD) Post-hoc multiple comparisons were used to establish the
means which were statistically different. The results are shown in Table 9.
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Table 9
Post Hoc Multiple Comparisons of Post- test of CAT Mean Scores for the Four Groups
Group Name Mean difference Standard error Significance
(i) (j) (i-j) p- value
E1 C1 8.20 3.37 0.02*
C2 7.27 3.53 0.04*
E2 -0.59 3.55 0.86
C1 E1 -8.20 3.37 0.02*
C2 -0.94 3.61 0.79 E2
-7.86 3.78 0.04*
E2 E1 0.59 3.55 0.86
C1 8.80 3.64 0.02*
C2 7.86 3.78 0.00*
C2 E1 -0.18 0.09 0.04*
C1 0.09 0.09 0.29
E2 -0.31 0.09 0.04*
* denotes that the mean differences are significant at 0.05 confidence level.
The results indicate that the differences in mean scores of groups E1 and C1, groups E1 and C2,
C2 and E1, C2 and E2, E2 and C1 were statistically significant at 0.05 levels. Therefore, HO1 is
rejected. The study showed that advance organizers are effective in enhancing students‟
achievement in Chemistry. The findings of this study are in agreement with that of Shihusa and
Keraro (2009) that the use of advance organizer teaching strategy results in higher achievement
of students in Biology. Wachanga and Mwangi (2004) also found out that cooperative class
experiment method facilitated chemistry learning more than RTM. Recent research by Njue
(2010) found out that students who were taught using constructivist teaching strategy (CTS)
achieved relatively higher scores in CAT in mole concept in Chemistry than those taught through
RTM. Results of this study show that there is merit in using advance organizer approach to
enhance students‟ achievement.
When students are given advance organizers prior to actual learning the learners‟ attention is
actually directed to the most important aspects of the lesson which involves what they are able to
pick from the lesson in terms of the understanding of the main concepts than the mere ability to
recall facts, definitions and formulae. Adebola (2011) found out that the use of advance
organizers is an effective strategy for teaching and learning Mathematics at senior secondary
school level. Adebola (2011) recommend that behavioral objectives and other forms of advance
organizers should be used by teachers of Mathematics in instructing their students at the
secondary level. Clawson and Bames (1973) attempted to determine the effects of different types
of advance organizers. Their work showed that advance organizers with pictorial, graphic and
manipulated materials were more effective than verbal and expository advance organizers.
Studies of what constitutes an advance organizer have produced conflicting conclusions while
inconsistent results have also been reported in literature on the use of advance organizers
(Adebola, 2011).The findings of this study indicate that the use of AOTA enhances Chemistry
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learning in the Mole Concept topic. Although teachers use advance organizers during teaching,
perhaps majority of the chemistry teachers are either not familiar or aware of the use advance
organizers and the role they play in Chemistry learning. Strengthening the use of advance
organizers through inservice courses could help science teachers to adopt proper use of the
advance organizers in teaching.
Effects of AOTA on Achievement of Boys and Girls in Chemistry
Independent samples t-test was used to analyze whether there was a significant difference in
CAT mean scores between boys and girls who were taught using AOTA. The results are shown
in Table 10.
Table 10
t- Test Results of the Post- test Mean Scores on CAT by Gender
Gender N Mean score (%) SD df t-value p- value
Male 34 30.00 15.18 83 -0.41 0.69
Female 51 31.57 18.69
Total 85
The results in Table 10 indicate that the differences in CAT mean scores between the male and
female students were not statistically significant, t (83) = - 0.41, p>0.05. Therefore, H03 was
accepted. The findings of this study indicate that gender has no significant effect on Chemistry
achievement when AOTA is used. The results of this study concur with that of Njue (2010) that
gender has no significant effects in chemistry achievement when students are taught using CTS
in the Mole Concept topic. The present study also concurs with those of Rizwan and Muhammad
(2005) findings that science achievement of female students was better than the science
achievement of male students although there were no significant differences in CAT mean
scores. In this study a chart in form of graphic organizer was used to provide a visual
representation of facts and concepts in an organized frame. Novak (1980) asserts that creative
teaching, when well done, includes the selection and use of good advance organizers. New
information about a concept is filled into an existing framework of categories called schemes that
contain specific information (Akinbobola, 2010). If no knowledge is available, advance
organizers are used to give knowledge to the students in order for this framework to be followed
and new information retained for recall and transfer.
Conclusions
Based on this study the following conclusions were made
i. Students who are taught through AOTA achieve higher chemistry learning than those
taught through RTM.
ii. Gender has no effect on students‟ achievement when they are taught through AOTA.
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References
Adebola, S.F. (2011). The Effects of Behavioral Objectives on Students‟ Achievement in
Senior Secondary School Mathematics Instruction when used as Advance Organizers.
American Journal of Scientific and Industrial Research. Accessed on:
http://www.scihub.org/AJSR on 6/7/2011.
Akinbobola, A.O, & Afolabi. (2010). Constructivist Practices through Guided Discovery
Approach: The Effects on Students‟ Cognitive Achievement in Nigerian Senior
Secondary School Physics. Eurasia Journal of Physics and Chemistry Education. 2 (1),
16-25.
Anderson , R. C. (2004). Role of the Readers‟ Schema in Comprehension, Learning and
Memory in R.B. Ruddel, & N. J. Unrau (Eds), Theoretical Models and Processes of
Reading (5th
ed.) pp 594-606. Newark, DE: International Reading Association.
Ausubel, D. P. (1960). The Use of Advance Organizers in the Learning and Retention of
Meaningful Verbal Material. Journal of Educational Psychology, 51, 2672.
Borg, W. R, & Gall. M. D. (1989). Educational Research. An Introduction. 5th
Ed. White
Plains. New York, U.S.A: Longman.
Bransford, J. D. (2004). Schema Activation and Schema Acquisition. Theoretical Models
and Processes of Reading (5th
Ed) Newark, DE: International Reading Association, Inc.
Clawson, E. U. & Bames, B. R. (1973). The Effects of Organizers on Learning of
Structured Anthropological Materials in the Elementary Grades. The Journal of
Experimental Education. 42(1), 11-15
Fraenkel, N., &.Wallen, E.(2000). How to Design and Evaluate Research in Education.
5th
Ed. New York, U.S.A: Mc Graw Hill.
Githua, N. B. & Nyabwa A. R. (2007). Effects of Advance Organizer Strategy during
Instruction on Secondary School Students’ Mathematics Achievement in Kenya’s’ Nakuru
District. Accessed on 04/01/2010
http://www.springerlink.Com/content/337474762640r124/
Mayer, R. (2003). Learning and Instruction. New Jersey. USA: Pearson Education, Inc
International Journal of Social Science & Interdisciplinary Research__________________________________ ISSN 2277 3630 IJSSIR, Vol. 2 (6), JUNE (2013) Online available at indianresearchjournals.com
36
Mugenda, O., & Mugenda, A. (2003). Research Methods. Quantitative & Qualitative
Approaches. Nairobi, Kenya: ACTS press.
Mutai, B. K. (2000). How to Write a Quality Research Proposal. A Complete and a
Simplified Recipe. 1st Ed. My Sore, India: My Sore University Press.
Njue, A. K.(2010). Effects of Constructivist Teaching Strategy on Students‟ Achievement
in Chemistry. Unpublished MEd Thesis. Chuka University College, Kenya
Novak, J .D.(1980). Learning Theory Applied to the Biology Classroom. A Useful Tool
for Science Education. The American Biology Teacher, 42,(5) 280-285
Rizwan, A.R. &Muhammad, Z. I. (2005). Effects of Students’ Self concept and Gender on
Academic Achievement in Science. Bulletin of Education and Research , 27(2), 19-36.
Shihusa, H. & Keraro, F. N. (2009). Using Advance Organizers to Enhance Students‟
Motivation in Learning of Biology. Eurasia Journal of Mathematics, Science and
Technology Education . 5(4), 413-420.
The Kenya National Examination (KNEC) (2008).The Kenya National Examinations
Council . Nairobi: Kenya.
The Kenya National Examination (KNEC) (2009). The Kenya National Examinations
Council. Nairobi: Kenya.
Thorne, M., & Giesen, M. (2000). Statistics for Behavioral Sciences. 3rd
Ed. London,
USA: Mayfield Publishing Company.
Wachanga, S.W. & Mwangi, J.G.(2004). Effects of Cooperative Class Experiment
Teaching Method on Secondary School Students‟ Chemistry Achievement in Kenyas‟
Nakuru District. International Education Journal 5(1). Accessed on 24/4/2012 http://iej.
J.c,b net
Webster, G. H. (2009). Attitude Counts. Self-Concept and Success in General
Chemistry. Journal of Chemical Education. 86, 6, p. 744.
Woolfolk, A. (2001). Educational Psychology. 8th
Ed. Boston, USA: Allyn and Bacon.