Asia-Pacific Forum on Science Learning and Teaching, Volume 9, Issue 2, Article 2 (Dec., 2008) Ayşe SERT ÇIBIK, Emine Hatun DİKEN & Emine Selcen DARÇIN The effect of group works and demonstrative experiments based on conceptual change approach: Photosynthesis and respiration Previous Contents Next

Results

Homogeneity of groups before treatment

This study was conducted on two groups, the experimental and control groups. In order have homogeneity in each group, pre-test scores of the photosynthesis and respiration in plants concept test were considered. In order to see whether there is a difference among different variables of groups, an independent sample t-test was conducted. The values of the mean scores, standard deviation, t values are listed below in Table I and Table II.

Table I. Control and experimental groups pre-test achievement scores on photosynthesis and respiration in plants concept test and independent t-test scores

Group	N		S	Sd	T	p (Significance)
Control	40	33.12	7.97	76	-0.929	0.356
Experimental	38	34.57	5.56
* p<0.05

When Table I was analyzed, no significant difference was found among pretest achievement scores of the control and experimental groups (t(76) = -0.929; p >0.05). Achievement test scores of experimental group students before treatment ( = 34.57) was higher than control group students’ score ( = 33.12), but this difference is not significant to the 95% confidence interval. This result shows that pre-service teachers’ conceptions on photosynthesis and respiration in plants are approximately same before the application. We can conclude that both groups have the equal concept knowledge.

Is there a significant difference among achievement scores of experimental group students who used group work and demonstrative experiments based on conceptual change approach compared to control group students who used traditional instructional methods in teaching concepts of photosynthesis and respiration in plants?

The photosynthesis and respiration in plants concept test was conducted as a post-test in experimental and control group. The result of Independent sample t-test scores is presented in Table II.

Table II. Control and experimental groups post-test achievement scores on Photosynthesis and respiration in plants concept test and independent t-test scores

Group	N		S	Sd	T	p (Significance)
Control	40	33.37	7.46	76	-3.301	0.001
Experimental	38	38.15	5.03
* p<0.05

As it is represented in Table II, there is a significant difference among the post-test achievement scores of control and experimental group (t(76) = -3.301; p < 0.01). Mean score of experimental group achievement ( = 38.15) is much higher than control group’s achievement ( = 33.37) score. This result represents that treatment used on experimental group dramatically enhanced students’ achievement. This result shows that, group work and demonstrative experiments based on the conceptual change approach reduce the misconceptions of pre-service teachers on the concept of photosynthesis and respiration in plants.

Is there a significant difference among experimental group students’ pre and post-test achievement scores?

Table III. Experimental group students’ t-test results with respect to pre and post-test students’ achievement scores 

Test	N		S	Sd	T	p (Significance)
Pre test	38	34.57	5.56	37	-2.806	0.008
Post test	38	38.15	5.03
* p<0.05

Table III indicates that there is a significant difference among pre test and post-test scores in the experimental group’s achievement test (t(37) = -2.806; p < 0.01). The mean score of students’ pre-test score is =34.57, and the post-test score is =38.15. This result shows that the treatment used on the experimental group dramatically enhanced students’ achievement. According to this data, it can be concluded that the applied method positively affected the conceptual success of pre-service teachers on photosynthesis and respiration in plants. Researches revealed that making use of different teaching strategies in classrooms positively affected the pre-service teachers’ learning of concepts (Haslam and Treagust, 1987; Alparslan, 2002; Köse et al., 2006).

Is there a significant difference among control group students’ pre and post test achievement score?

Table IV. Control group students’ t-test results with respect to pre and post-test students’ achievement score  

Test	N		S	Sd	t	p (Significance)
Pre test	40	33.12	7.97	39	-0.126	0.900
Post test	40	33.37	7.46
* p<0.05

Table IV shows that there is no significant difference among pre test and post-test scores of students’ achievement test in the control group (t(39) = -0.126; p < 0.01). The mean score of students’ pre-test in the achievement test is  = 33.12, and the post-test score is = 33.37. This result reveals that traditional approaches used on the control group did not enhance students’ achievement.