BIB_09: Strybel, T. Z. (2005). Task analysis for the design of Web applications. In R. W. Proctor & K.-P. L. Vu (Eds.), Handbook of human factors in Web design (pp. 385-407). Mahwah, N.J.: L. Erlbaum Associates.

In this chapter, Strybel surveys methods of task analysis in human factors and their application in designing web-based applications. The author first offers a brief history of task analysis since the early 20th century. He then discusses the characteristics of task analysis and emphasis on a goal-oriented approach. Strybel summarizes the sources of data utilized in task analysis to include task documents, direct observation (think aloud protocol & user comments), structured interviews, surveys, performance logs, and discusses the application of task analysis in personnel selection and training, system function identification and allocation, interface design, measurement of mental workload, testing and evaluation of system design, and user performance modeling. Strybel continues to discuss about the criticism of task analysis from practitioners and behavioral scientists. For some practitioners, formal task analysis methods are not cost effective. On the other hand, behavioral scientists are concerned about the validity of these methods. Strybel then provides a detailed discussion about the task analysis methods that are suitable for web application design, such as hierarchical task analysis (HTA), critical incident technique (CIT), a cognitive task analysis method GOMS, and other methods such as timeline analysis, link analysis, position analysis questionnaire abilities requirements analysis, and sequence and flow description. In conclusion, Strybel recommends that task analysis can yield greatest benefits when applied early in the design process. He also recommends to start task analysis with a flexible, breadth-first method, prioritize user goals, choose appropriate methods for user groups being targeted for additional analyses, and carefully document the process and outcomes.

The chapter provide a good survey of task analysis methods in the field of human factor. This survey is good for technical communicators who are interested in web design and usability to have some understanding of a closely related field. Some of the overall perspectives in the chapter are insightful. For instance, Strybel makes the distinction between a "system-centered" approach and an "object-oriented" approach in terms of their assumptions about users' goals: "In the system-centered approach, the user's task goals are assumed to be compatible with system goals. In object-oriented design, the users' goals may be different from those of a larger system. Regardless, the assumption of goal-oriented behavior implies that an understanding of the users' goals, tasks, knowledge requirements, and performance constraints are necessary to predict and improve task performance" ( p. 387). Also, the sources of data are useful for technical communicators in data collection. However, to apply the methods discussed in this chapter in the field of technical communication, careful adapting work has to be done.