Description

Video recording is a technique rather than a method. It is often used as an intermediary where direct observation is not practical.

Discussion/Reference

Video Recording is a technique, rather than a method, providing what seems at first to be a means of preserving the activities recorded for more leisurely analysis. There is a temptation, when planning a study, to include video-recording of the entire process. This is often a waste of time and resources, leading only to racks of poorly identified tapes in storage.

The definition available on standard domestic video-cameras and camcorders is not sufficient to provide readable copies of video displays. Recordings may also be affected by synchronisation problems, producing dark bands on the display image.

Professional video experts are aware of these problems, and have ways of avoiding them. As a minimum, S-VHS rather than VHS recording should be used.

It is increasingly easy to use direct digital recording. Although the amount of storage required appears considerable, sophisticated data reduction and storage techniques are readily available.

Some additional techniques are available which may simplify the analysis of video recordings. Multiple cameras may be recorded on a single record, either as split screen images, where each camera frame contains images from several cameras (with reduced precision), or by storing successive images on the same tape. The latter technique provides images which are as good as separate recordings, but at wider intervals. Some systems weight the sampling frequency according to the changes taking place in the images, so that a camera observing a vacant work position would take very few images, while one where intense activity was taking place would be sampled with maximum frequency.