The purpose of this study was to develop a data gathering technique which has all the advantages of verbatim data capture coupled with the ease of data input, storage, and analysis by a microcomputer coupled with an optical, mark-scanning machine. The problem for this study was to develop and test a comprehensive list of teacher behavior descriptors to be used as a resource in interpreting holistic data capture during a classroom observation and to develop a means for encoding all necessary data describing salient teachers' and students' classroom behaviors in a format suitable for optical scanner input to a microcomputer;This study had an experimental group of 57 and a control group of 58. Subjects were located in three different training sites (i.e., Iowa, Pennsylvania, and Kansas). The experimental group received time to review the training manual and practice at least two trial exercises of observing classroom simulation videotapes, script taping, and recording data on the formative 22-item computer evaluation form. The control group received time to read "placebo" material and also view the same classroom simulation videotape, script tape, and devise their own means of recording data. Finally, both groups completed a computerized summative evaluation form consisting of ten items. This summative instrument was developed by selecting the most appropriate items directly from the formative instrument. The scores from both groups were compared with those of the "expert jury's." This Iowa State University jury consisted of a team of individuals knowledgeable in effective teaching research;The experimental group scored significantly higher than the control group. The control group had a mean score of 4.38, while the experimental group had a mean score of 7.00. The difference was significant at the.01 level;This research supports the importance of a training manual (containing both definitions and examples) to support a quality instrument for interpreting classroom data capture. At the conclusion of each training session, participants were provided with the opportunity to verbally respond concerning the format and scope of the instrument. Minor revisions will be made and further research will continue.