Much of the research on students' understanding of the greenhouse effect and global warming reports poor results. Students are claimed to hold misconceptions and naive beliefs, and the impact of teaching on their conceptions is also low. In the present study, these results are called into question, and it is argued that they may to a large extent…

Describes a competency assessment system developed for use with preservice and inservice teachers and reports the reliability and validity of the instrument. Presents data from a tryout of the assessment system with a group of preservice science teachers. (CS)