Letter to the Editor—Comments on a Paper by Yarnold and Nehnevajsa

I would like to comment on the Yarnold and Nehnevajsa article (Yarnold, K. W., Jiri Nehnevajsa. 1961. Analytical methods for determination of training-device requirements. Opns Res.9 535–545.) appearing in the July–August 1961 issue. The comments fall into two categories: first based on the authors' assumption that “training devices” operate by improving the temporal-accuracy performance of a system's human links, and a second set of comments based on another assumption (mine) that humans can be trained by “training devices” continually to make improvements in and better diagnose problems of the entire man-machine system.