Altering depth and complexity in the science curriculum for the gifted: results of an experiment

Academic Achievement

Table 4 shows that the difference in academic achievement between the pre- and post-test scores in the treatment group was significantly in favor of the post test at the 0.05 level (z=-2.81, p<0.05, r=-0.88). A similar result was not found among gifted students in the control group (z=-1.78, p>0.05, r=-0.59).

Table 4. Results of the Wilcoxon Signed Rank Test Regarding Academic Achievement Pre and Post Test Scores of the Treatment and Control Groups

Groups	Pretest-Posttest	N	Mean Rank	Sum of Ranks	Z	p
Treatment	Negative Ranks Positive Ranks Ties Total	0 10 0 10	0 5.5	0 55	-2.81	.005
Control	Negative Ranks Positive Ranks Ties Total	2 7 0 9	3.75 5.36	7.5 37.5	-1.78	.075

Note. *p < .05, two tailed.

Table 5 shows that the difference in the academic achievement post-test scores between the two groups was found to be significant at the 0.05 level in favor of the treatment group (z=-2.084, p<0.05, r=-0.64).

Table 5. Results of the Mann Whitney U Test Regarding the Academic Achievement Post Test Scores of the Treatment and Control Groups

AA Post Test Scores	N	Mean Rank	Sum of Ranks	U	Z	p
Treatment Control	10 9	12.5 7.22	125 65	20	-2.048	.041

Note. *p < .05, two tailed.

Scientific Process Skills

Table 6 shows that the difference between the scores of the treatment group was significantly in favor of post test at the 0.05 level (z=-2.82, p<0.05, r=-0.89); however, a similar result was not found among the participants in the control group (z=-.120, p>0.05, r=-0.04).

Table 6. Results of the Wilcoxon Signed Rank Test Regarding the Scientific Process Skills Pre and Post Test Scores of the Treatment and Control Groups

Groups	Pretest-Posttest	N	Mean Rank	Sum of Ranks	Z	p
Treatment	Negative Ranks Positive Ranks Ties Total	0 10 0 10	0 5.5	0 55	-2.823	.005*
Control	Negative Ranks Positive Ranks Ties Total	3 6 0 9	7.17 3.92	21.5 23.5	-.120	.905

Note. *p < .05, two tailed.

Table 7 shows the difference in the scores between the two groups was found to be significant at the 0.05 level in favor of the treatment group (z=-1.98, p<0.05, r=-0.62).

Table 7. Results of the Mann Whitney U Test Regarding the Scientific Process Skills Post Test Scores of the Treatment and Control Groups

SPS Post Test Scores	N	Mean Rank	Sum of Ranks	U	Z	p
Treatment Control	10 9	12.4 7.33	124 65	21	-1.98	.047*

Note. *p < .05, two tailed.

Attitude toward Science education

Table 8 shows that the difference between the scores of the treatment group was significantly in favor of the post test at the 0.05 level (z=-2,25, p<0.05, r=-0.75), and a similar result was found in the control group (z=-2.53, p<0.05, r=-0.84).

Table 8. Results of the Wilcoxon Signed Rank Test Regarding the Attitude Scale toward Science and Technology Course Pre and Post Test Scores of the Treatment and Control Groups

Groups	Pretest-Posttest	N	Mean Rank	Sum of Ranks	Z	p
Treatment	Negative Ranks Positive Ranks Ties Total	1 7 1 9^a	2.00 4.86	2.00 34.00	-2.25	.024*
Control	Negative Ranks Positive Ranks Ties Total	0 8 1 9	0 4.50	0 36	-2.53	.011*

Note.^aOne student in the treatment group did not want to be tested on the attitude scale.
*p < .05, two tailed.

Table 9 shows that the difference in the scores between the two groups was not significant at the 0.05 level in favor of either the treatment group or the control group (z=-1.06, p>0.05, r=-0.35).

Table 9. Results of the Mann Whitney U Test Regarding Attitude Scale toward the Science and Technology Course Post Test Scores of the Treatment and Control Groups

SPS Post Test Scores	N	Mean Rank	Sum of Ranks	U	Z	p
Treatment Control	9 9	8.11 10.99	73 98	28	-1.06	0.29