“…Two other studies employing educational print materials suffered from lack of control groups or preintervention observations and should thus be interpreted cautiously. Watson, Stenhouse, and Jellett (1975) utilized concurrent regional and nationwide comparison groups to monitor changes in the prescribing practices of 430 general practitioners in the state of Western Australia who were sent information in a handy index‐card format. Recommended therapies were based on common problems identified by an audit and expert review of prescription practices.…”