This study was conducted to examine how teachers' beliefs about computer-assisted instruction (CAI) relate to the types of instructional software they use with students, the types of computer related activities they provide for their students, whether they integrate computer usage with other instructional activities, and whether they had received training in various types of computer usage. Data were collected through a survey mailed to every public elementary, middle, junior high, and high school in one state. A total of 2,170 usable surveys (63 percent) were returned. The questionnaire contained items which focused on: teacher demographics; beliefs about the effectiveness of using computers in instruction; the amount, frequency, and type of CAI teachers engaged in; frequency of use; subject areas for software used; and the types of technology training they had received. According to the data analysis, teachers' beliefs about effective use of technology for instructional purposes can be differentiated into two discrete categories: some teachers believe that computers are tools that students use in collecting, analyzing, and presenting information, while others believe that computers are teaching machines that can be used to present information, give immediate reinforcement, and track student progress. In general, elementary school teachers favored a more transmission oriented view of how computers can be effectively used, while secondary teachers tended to favor a more constructivist view. (Contains 16 references.) (LL)