There are many varieties of task analysis-each with its advantages and disadvantages, each with its adherents and detractors (e.g., see the recent collections published by Annett & Stanton, 1998; Kirwan & Ainsworth, 1992). Most published descriptions focus on how to apply the technique or why it is a good technique to apply. Few accounts written by advocates of a technique are specifically directed at problems and pitfalls in applying the technique. This account is different. Although we are unabashedly enthusiastic advocates of the theory-driven combination of task analysis and protocol analysis that we employ, we hope that by identifying problems and obstacles that we encountered that more people will be better prepared and, therefore, more successful at applying these techniques.