ABSTRACT
What they had in mind, and this is illustrated in many of the analyses later carried out by Keith Duncan and Andy Shepherd, was that HTA would identify what the operator had to know. For example, the meaning of various possible stimulus patterns (both input and feedback) and rules and principles which determine (or inform) decisions and actions. One of the main purposes of the people involved in the development of HTA was to add a cognitive dimension to the (then) standard methods of analysing tasks. Clearly they anticipated CTA by a decade or more!
