Shining, Good varaitaion. I think we always have to be sensititive to "what is the best way to teach this subject to these students at this time". It will vary each time, and using a variety of media will encourage participation and retention of needed information by the students. PPT is a great tool, but is limited unless the instructor uses this tool to supplement their lectures and accompany other instructional media. Too many times reading PPT slides with too much information is considered the lecture, and this is probably the least effective methods for learning. Barry Westling