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Asia-Pacific Forum
on Science Learning and Teaching, Volume 12, Issue 2, Article 7 (Dec., 2011) |
Analysis of covariance and multiple classification analysis were used to analyze the data.
Source of variance
Hierarchical Method.
sum of squares
df
Mean squares
f
sig
covariates
1267.081
1
1267.081
17.161
.000
Main effects (combined
30197.93
5
6039.589
81.800
.000
Treatment
28133.26
2
14066.63
190.518
.000*
Model
34899.69
18
1938.872
26.210
.000
Residual
20747.28
281
73.834
Total
55646.97
299
186.110
* P < 0.05 significant result.
Table 2: Summary of ANCOVA of post-pest achievement scores of students’ by Treatment.
Table 2 shows that there is a significant main effect of treatment on students’ achievement in chemical kinetics (F [2, 281) = 190.518; P < 0.05). This implies that the post-test scores of students in chemical kinetics differ significantly across the two experimental groups and control. Hypothesis 1 was therefore rejected. To determine the magnitude of the mean scores of each of the three groups, the multiple classification analysis (MCA) was computed and presented in Table 3.
Treatment + category
N
Unadjusted
Adjusted for factors and covariates
Unadjusted deviation
ETA
Adjusted for factors and covariates development.
BETA
TREATMENT 1 coop/comp
100
40.8400
38.98
- 12.65
0.657- 14.51
0.7542. coop 3. control Multiple R R2
0.565
Table 3: Multiple classification analysis of post-test achievement scores according to treatment.
From Table 3 students’ exposed to STAD ii (without competition) obtained the highest mean achievement score in chemical kinetics (x = 61.16). Those in the control group scored next to them (x = 60.23) while the students in STAD I with competition had the lowest achievement scores (x = 38.98). In probing further into the source of the significant difference observed in table 3 Scheffee post-hoc analysis was carried out. The result was presented in table 4 .
Treatment
X
1.STAD I (Comp)
2. STAD ii (without comp)
3. control
- STAD I (with competition)
38.98
*
*
- STAD II (without competition )
61.16
*
- Control
60.23
*
* Pairs of groups significantly different at P <. 05.
Table 4: Scheffe post-Hoc. Analysis of treatment effects on students’ achievement.
From table 4, results showed that the achievements of students differ significantly when those in group I (STAD with competition) was compared with group ii (STAD without competition) with mean scores 38.98 and 61.16 respectively. Also students’ in group I (x = 38.98) differ significantly from those in the control group (x = 60.23). These results revealed that STAD ii without competition and control group were quite close in mean achievement scores of students and the pair did not contribute to the .significant effect of treatment.
Table 5, revealed that there was a significant main effect of treatment on students attitude to chemical kinetics (F (2, 281) = 379.25; P < .05). The result implied that the post-test attitude scores of the students exposed to the different treatment conditions were significantly different. Hence hypothesis 2 was rejected.
Source of variance
Hierarchical Method.
sum of squares
df
Mean squares
f
s.g
Covariates
7713.561
1
7713.561
111.294
.000
Main effects (combined
53404.05
5
10680.81
154.106
.000
Treatment
52573.69
2
26286.84
379.275
.000*
Model
63566.09
18
3531.449
Residual
19475.58
281
69.308
50.953
.000
Total
83041.67
299.
277.731
* Significant at <.05
Table 5: summary of ANCOVA of post-test attitude scores of students’ according to treatment.
To find the magnitude of the post-test mean attitude scores of subjects exposed to the different treatment conditions, the multiple classification analysis (MCA) presented in table 6 was computed.
Treatment + category
N
Unadjusted
Adjusted for factors and covariates
Unadjusted deviation
ETA
Adjusted for factors and covariates development.
BETA
TREATMENT
1, coop/comp 2. coop 3. control R R2
.736
Table 6: Multiple classification analysis of post-test attitude scores by treatment.
Table 6 revealed that Students in STAD 1 (with competition) group had the highest mean attitude score (x = 52.06) followed by those in the group treated with STAD 2 (without competition) (x = 25.23) while the control group obtained the lowest (x = 21.41).
In order to trace the source of significance observed in table 6, the scheffe post-hoc analysis was carried out in table 7,
Treatment
X
1.STAD I (Comp)
2. STAD ii (without comp)
3. control
- STAD I (with competition)
52.06
*
*
- STAD II (without competition )
25.23
*
- Control
25.41
*
*
* Pairs of groups significantly different at P <. 0.05
Table 7: Post-Hoc analysis of treatment effect on students’ attitude to chemical kinetics.
It was obtained from table 7, that each of the three possible pairs of groups was significantly different from the other in students’ attitude toward chemical kinetics
