Pre-course results from the astronomy diagnostic test

We present selected results from the January 1999 semester pre-course admin istration of the Astronomy Diagnostic Test (ADT), a research-based, multipl e-choice instrument that assesses student knowledge and understanding about selected concepts in astronomy. The ADT is valid for undergraduate non-sci ence majors taking an introductory astronomy course. This paper briefly sum marises the development and validation processes, which included pre-course administration to 1557 students in 22 classes attending 17 various post-se condary institutions across the USA in the January 1999 semester. Two inter esting results of the ADT's pre-course administration are (1) the average c lass score of the ADT is about the same (32%) regardless of type of post-se condary institution or class size and (2) there is a significant gender dif ference, with women scoring an average of 28% and men 38%, with the standar d errors both Less than 1%. The current version of the ADT (Version 2 dated 21 June 1999) and a comparative by-class database is available to astronom y instructors at the (USA) Association of Astronomy Educators' and the Nati onal Institute for Science Education's (NISE) WebPages.