We present a detailed case study of a computer scientist learning and
using the Cognitive Walkthrough (CW) technique to assess a multimedia
authoring tool. We then compare the predictions produced by the analys
is to the usability problems actually found in empirical usability fas
ts. In this case, the concepts of Cognitive Walkthrough were learnable
by the analyst who had little prior training in psychology or Human-C
omputer Interaction, flexible enough for the analyst to make reasonabl
e modifications to the technique to fit the design situation, but disa
ppointingly ineffective in predicting actual user problems, We present
several hypotheses about the cause of low effectiveness, which sugges
t that additional knowledge, currently tacit in CW-experts, could be u
sed to improve the technique, in addition, the emergent picture of the
process this evaluator went through to produce his analysis sets real
istic expectations for other novice analysts who contemplate learning
and using Cognitive Walkthroughs.