What is Ethnography
Software systems do not exist in isolation-they are used in a social and organizational context, and software system requirements may be derived or constrained by that context. Satisfying these social and organizational requirements is often critical for the success of the system. One reason why many software systems are delivered but never used is that they do not take proper account of the importance of these requirements.
Ethnography is an observational technique that can be used to understand social and organizational requirements. An analyst immerses him or herself in the working environment where the system will be used. He or she observes the day-to-day work and notes made of the actual tasks in which participants are involved. The value of ethnography is that it helps analysts discover implicit system requirements that reflect the actual rather than the formal processes in which people are involved.
People often find it very difficult to articulate details of their work because it is second nature to them. They understand their own work but may not understand its relationship with other work in the organization. Social and organizational factors that affect the work but that are not obvious to individuals may only become clear when noticed by an unbiased observer.
Suchman (Suchman, 1987) used ethnography to study office work and found that the actual work practices were far richer, more complex, and more dynamic than the simple models assumed by office automation systems. The difference between the assumed and the actual work was the most important reason why these office systems have had no significant effect on productivity. Other ethnographic studies for system requirements understanding have included work on air traffic control (Bentley, et al., 1992; Hughes, et al., 1993), underground railway courtrooms (Heath and Luff, 1992), financial systems, and various design activities (Heath, et al., 19999 Hughes, et al., 1994).
In my own research, I have investigated methods of integrating ethnography into the software engineering process by linking it to requirements engineering methods (Viller and Sommerville, 1999; Viller and Sommerville, 1998; Viller and Sommerville, 2000) and by documenting patterns of interaction in cooperative systems (Martin, et al., 2001; Martin, et al., 2002; Martin and Sommerville, 2004).
Ethnography is particularly effective at discovering two types of requirements:
Requirements that are derived from the way in which people actually work rather than the way in which process definitions say they ought to work. For example, air traffic controllers may switch off an aircraft conflict alert system that detects aircraft with intersecting flight paths even though normal control procedures specify that it should be used. Their control strategy is designed to ensure that these aircraft are moved apart before problems occur and they find that the conflict alert alarm distracts them from their work.
Requirements that are derived from cooperation and awareness of other people's activities. For example, air traffic controllers may use an awareness of other controllers' work to predict the number of aircraft that will be entering their control sector. They then modify their control strategies depending on that predicted workload. Therefore, an automated ATC system should allow controllers in a sector to have some visibility of the work in adjacent sectors.
Ethnography may be combined with prototyping (Figure 7.9). The ethnography informs the development of the prototype so that fewer prototype refinement cycles are required. Furthermore, the prototyping focuses on the ethnography by identifying problems and questions that can then be discussed with the ethnographer. He or she should then look for the answers to these questions during the next phase of the system study (Sommerville, et al., 1993).
Ethnographic studies can reveal critical process details that are often missed by other requirements elicitation techniques. However, because of its focus on the end-user, this approach is not appropriate for discovering organizational or domain requirements. Ethnographic studies cannot always identify new features that should be added to a system. Ethnography is not, therefore, a complete approach to elicitation on its own, and it should be used to complement other approaches, such as use-case analysis
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