Student time-on-task for prelabs in Instrumental Analysis during 1997 and 1998. Student responses to Statement 1: "Doing the prelab exercises helped prepare me for the upcoming laboratory work?" The grade during 1997 was full credit for on-time completion regardless of the answer given. The grade recorded during 1998 for on-time completion was full credit for the correct answer and half credit for an incorrect answer. No credit was given for completing a prelab late.