Helical scan video tape recorders were tested for their dubbing characteristics in order to make selection data available to media personnel. The equipment, two recorders of each type tested, was submitted by the manufacturers. The test was designed to produce quality evaluations for three generations of a single tape, thereby encompassing all levels of probable use in the school situation. The experiment tested four conditions: making a recording and playing it back; playing the recording back on a second machine; making a copy of the recording and playing it back; and making a recording of the copy and playing it back. This representation in the study appears in two forms: on the standard waveform monitor, which has meaning for the engineer; and on a picture monitor, which has meaning to the media specialist. For each of the four experimental conditions, still photographs of the waveform oscilloscope image and the picture monitor image were made to analyze performance and for reproduction in the report. Various design elements in the recorders studied determine their value for various uses. The conclusion is that there are three groupings of recorders based on picture quality and price range. When the intended use has been determined, the appropriate grade of machine may then be selected from one of the groups. (MT)