Modeling Human–System Interaction

6 ANALYZING THE INFORMATION

TASK ANALYSIS

A standard human factors technique is task analysis. A task analysis can be said to be a model of the task.

In addition to the form such as the one shown in Figure 6.1, task analyses are often represented as flow charts that can show contingencies (for multiple paths that are dependent on fulfillment of given conditions), feedback loops, and so on. Common instructions on how to assemble products (delivered in parts) often complement the task analysis using simple pictures with arrows. Computer programs are a form of task analysis for the computer. Sometimes, a task analysis of what a human operator is required to do is interlinked on a step‐by‐step basis with a description of what a computer is supposed to do. Detailed task analyses of this type are developed as a common communication basis for engineers, trainers, and pilots regarding operations of aircraft and spacecraft (Kirwan and Ainsworth, 1992).

FIGURE 6.1 A hypothetical form for performing a task analysis.

JUDGMENT CALIBRATION

Expert and/or user judgments are critical in designing a machine or a policy. One of the most straightforward problems of extracting judgment information from a person is the degree to which the judgments people render about the values of variables in the physical world are biased. This problem has a solution, for those judgments can be ...