Human Factors Considerations in System Design

Human factors considerations in systems design was examined. Human factors in automated command and control, in the efficiency of the human computer interface and system effectiveness are outlined. The following topics are discussed: human factors aspects of control room design; design of interactive systems; human computer dialogue, interaction tasks and techniques; guidelines on ergonomic aspects of control rooms and highly automated environments; system engineering for control by humans; conceptual models of information processing; information display and interaction in real time environments

Interfaces to encourage look-ahead : impact on problem solving and performance

The experiments reported in this thesis attempted to directly study the process of look-ahead during problem solving. Recent work has suggested that interface manipulations that increase look-ahead during problem solving lead to improvements in performance. However, evidence has been indirect, and there have been few attempts specifically made to quantify look-ahead span, changes that may occur over time and possible interactions with the task environment. An initial experiment required users to specify 3 moves in advance while solving the 8-puzzle. The strict enforcing of look-ahead by even a small number of moves was unsuccessful in terms of improving problem performance. In fact, results indicated that such move enforcement may negatively affect performance. Subsequent experiments, using both the 8-puzzle and Water Jars problems, provided participants with a motivation to plan using a Scoreboard system that rewarded greater planning and look-ahead. Results found this approach to be more viable, as the interface appeared to support the opportunistic planning behaviour frequently undertaken by participants. Across a series of experiments, increased look-ahead led to more efficient problem solving performance compared to controls, while leaving total time to solution unaffected. Look-ahead span increased to approximately 11 steps when transforming the same start-state to a goal-state over trials on the 8-puzzle. When a new solution path had to be generated for each new problem start-state, look-ahead still increased over trials, but only to a span of approximately 4 steps. This look-ahead span was also observed during Water Jars performance when the Scoreboard manipulation was present. A manipulation of 'system response time' (SRT) on Water Jars problems also led to improved performance but indicated an adaptation to the manipulation, leading to a lesser impact of SRT than previous manipulations. The results are discussed in relation to existing studies of planning, performance and the role that look-ahead may have in future studies of problem solving