Background/Question/Methods Can video introductions to field sites, equipment, and methods enhance performance of teaching assistants and students in a large general ecology course? Iowa State University's general ecology course (10 lab sections, total of 240 students) uses an inquiry-based approach in which students have a significant role in designing their lab exercises, most of which are carried out in the field. A basic problem with this approach is that the students must design the exercises before having seen the field sites or having any experience with appropriate sampling techniques and equipment in the field. We filmed videos at local field sites and in the lab to familiarize both teaching assistants and students with field sites near Ames, IA where they will conduct field studies and with the basic methods and equipment that they will use. A total of ten videos for four lab exercises was shown in fall 2007. The effectiveness of these videos was assessed by making both within- and between-year comparisons of student evaluations of labs with and without videos.

Results/Conclusions Comparisons of lab exercises in fall 2007 with and without videos showed a significantly higher ranking of lab exercises with videos. To account for potential effects of instructor and lab exercise topic, a more-detailed analysis compared lab exercises from 2007 with the same exercises from 2006, when no videos were used, and incorporated instructor evaluations and lab topic as covariates. This analysis also showed that rankings were significantly affected by use of videos, although there is considerable year-to-year and within-year variation in lab exercise evaluations due to topics, different lab instructors, and probably other sources such as students. Production of videos requires considerable time, but modern equipment of relatively low cost allows even modestly-skilled course instructors to produce a high-quality product specifically tailored to local course needs.