THE HUMAN FACTOR HAS KNOCKED THREE TIMES Three books on the ergonomics of computing systems

What is the best way of building user-friendly computing systems? This is undoubtedly a naive question but its importance will be recognized by any user of ~resent~day systems. Specialists in this field of research give vanous names to it: the ergonomics of computing systems, the study of human factors, software psy~hology, hu:r:an engineering, user psychology, user SCience, cognItive engineering, etc. The lack of a single agreed term is a clear sign of how young the discipline is, and of the lack of concrete results produced in it to date. But, unquestionably, its current development meets a need which is increasingly widely felt. The three books reviewed here approach this subject from rather different points of view. The earliest (1980) ~s Shneiderman's, which gives the broadest coverage and IS concerned with all psychological problems linked with software, i.e. not merely with the use of programs (which is what concerns us here) but also with their production. Ledgard, Singer and Whiteside (1981) deal with the study of 'human factors'. Like Schneiderman, the authors are computer scientists concerned with making the systems they have produced more user-friendly. The most recent work, by Card, Moran and Newell which had just appeared as I began this review has a different slant: it is a very concise examination of the 'cognitive' aspects of the use of interactive systems, based on the results of current research in cognitive psychology. The approach is mu!t!disciplinary: although at least one of the au~ors (~ewell) 1S well known in the computer science field (10 partIcular that of artificial intelligence), most of the references in their bibliography are extracts from reviews such as Cognitive Psychology, Journal of Experimental Psychology, etc.