In this study, the effect of problem-based learning on students' academic achievement and performance skills in a unit on the human excretory system was investigated. Sixty-one 10th grade students, from two full classes instructed by the same biology teacher, were involved in the study. Classes were randomly assigned as either the experimental or…

The study presents the frequencies of students' conceptions of growth and cell division before and after one hour of instruction. The investigation supplements qualitative results by directing attention to those conceptions which might occur most frequently to students: teachers can then concentrate their preparation on practical requirements. A…