Integrating Human Computer Interaction with Jackson System Development

Procedures for integrating task analysis and design of the human computer interface with a structured system development method, Jackson System Development (JSD), are described. Process Structure Diagrams, the major modelling notation of JSD, were used to specify tasks which were analysed to predict cognitive complexity. Task complexity analysis helped allocation and design of human tasks to produce task support specifications. The cognitive dimension of task analysis highlighted the need for task support actions, especially design of information displays to support working memory. Dialogue specification for dialogues and interface displays were based on the task analysis and information requirements. Further analyses addressed the timing constraints on human and computer actions, and derivation of display requirements from task-related information needs. Preliminary evaluation of the method showed the method proved easy to learn even for non HCI specialists.