This paper examines two different delivery methods, video and computer-based instruction (CBI) for instructing preservice teachers in the use of an electronic mail system, FIRNMAIL. Three questions were asked about students who were taught FIRNMAIL through a video presentation and those taught through an interactive, computer-based simulation (CBI): (1) Is there a difference in the mean achievement gains on a writing post-test? (2) Is there a difference in students' perception of instruction? (3) Is there a difference in the mean near-transfer performance? Twenty-four students were randomly assigned to either the video or the CBI. Pre- and post-tests indicated that both treatments are instructionally effective. In analysis of perception of instruction it was found that students in the computer-based tutorial/simulation group were more likely to: enjoy the instruction; prefer their mode of instruction over a lecture; want another lesson like this; and prefer their mode of instruction over reading the material in a book. Analysis of near-transfer performance revealed that students in the CBI group performed significantly better on the electronic mail assignment than the students in the video group. Data is presented in three tables and four figures. (Contains 34 references.) (Author/MAS)