Development of knowledge frameworks and higher order cognitive operations among secondary school students who studied a unit on ecology

Thirteen randomly selected 9th and 10th grade students who studied an ecolo gy unit were interviewed, and the tape-recorded data analysed for changes i n organisation of knowledge, represented by ideational networks and the dev elopment of higher cognitive operations. Flow maps and content analysis, us ing a list of cognitive information processing categories, were used to ana lyse the tape-recorded narrative. The structure of the student knowledge be came increasingly advanced, as represented by increasing complexity of stud ent ideational networks. The network complexity closely paralleled the deve lopment of higher order cognitive operations, as evidenced in interview dat a. This research provides insights into how students develop knowledge sche mata, ideational networks, and the capacity to express ecological understan dings using higher order cognitive operations over several weeks.