Protocol analysis

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Protocol analysis provides a means for eliciting persons' thoughts while they are performing a task. Protocol analysis was invented by Newell and Simon (1984). Protocol analysis is undertaken in real time and, if carried out in the subject's natural environment, capture the context of events (Yin, 1994).

[edit] Method

Protocols are usually carried out in a subject's own environment. Usually teams are observed rather than individuals. The researcher may take notes, record video or audio while observing the subject. The participants are requested to think aloud whilst being observed. Observations, together with thinking aloud, can only provide a short, but detailed insight into the activities of designers. The effects of thinking aloud on the behavior of the designers are considered to be negligible if participants are only prompted to speak during periods of silence. Ericsson and Simon (1993) found no reliable evidence that structural changes occurred to the cognitive processing if subjects were simply asked to verbalize their thoughts. However, they found changes when subjects were asked to explain their cognitive processes.

[edit] Disadvantages

  • For each hour of protocol, an additional 25 hours may be required 12 hours for planning the observations and transcription and analysis (Ahmed, 2001).
  • Protocol analysis only captures specific episodes of activity.
  • Sometimes protocol analysis is done in the lab. Sometimes the experimenter goes to the subject. Observing in the environment of the subjects has the advantage of being in a real-life situation. However, it is less controlled than a laboratory experiment. * As protocols capture data in real time, participant bias, common with retrospective methods such as interviews and questionnaires, is avoided, but the observer's bias may have some effect (Staufferet al., 1991; Frankfort-Nachmias and Nachmias, 1996; Orne, 1969; Rosenthal,1966).