The following study investigated cognitive factors involved in applying the Perspective-Based Reading (PBR) technique for defect detection in software inspections. Using the protocol analysis technique from cognitive science, the authors coded concurrent verbal reports from novice reviewers and used frequency-based analysis to consider existing research on cognition in software inspections from within a cognitive framework. The current coding scheme was able to describe over 98% of the cognitive activities reported during inspection at a level of detail capable of validating multiple hypotheses from literature. A number of threats to validity are identified for the protocol analysis method and the parameters of the current experiment. The authors conclude that protocol analysis is a useful tool for analyzing cognitively intense software engineering tasks such as software inspections.