Table 5 indicates that grade level significantly affected students’ motivation in science, attitudes toward science and science achievement. Except for achievement and active learning strategies scales, there was a change in scale values of SMTSL for students’ grade level. Post-hoc comparisons using the Turkey HSD test indicated that the mean scores of Self Efficacy, Performance Goal and Science Achievement for 8th grade students were significantly different from 6th and 7th grade students. Sixth grade students’ mean scores for Science Learning Value and Learning Environment Stimulation were significantly different from those of 7th and 8th graders.
In order to investigate the effect of motivation levels on science attitude and achievement, students’ mean scores for science learning motivation were categorized as high motivation (N= 57), moderate motivation (N=256) and low motivation (N= 63). High motivation level included means scores between 4.41 and 5.00; moderate motivation level included means scores from 4.40 to 3.39 and finally low motivation level included mean scores below 3.38. Students’ motivation levels labeled regarding Table 6 showed the comparison of students’ science attitude and achievement scores using ANOVA regarding motivational levels.