Chapters 4 and 5 discuss how verbal data can be analysed and interpreted within a theoretical framework. The emphasis of these chapters is on the extent to which talking aloud, thinking aloud, and retrospective reporting provide relevant and systematic data that can be accounted for by a theory, in particular, the processing model introduced in chapter I.
Chapter 6 and 7 describe how to collect and analyse verbal protocols. These chapters, along with the appendix, make this a 'how to' book for those who wish to use verbal protocol methodologies. The authors do not simply argue for the validity of verbal reports, but also provide a detailed discussion about how to conduct this type of research. This is one of the most notable strengths of this book.
The preface contains a literature review that discusses several recent studies that are directly relevant to the arguments put forth in the main text of the book. The range of studies cited and discussed is impressive. A majority of these studies support the claims that thinking and talking aloud do not alter normal processing and that they provide a rather complete account of what is attended to during processing. Despite the breadth of the review, I believe the authors are, unfortunately, overly optimistic regarding the status of verbal reports in mainstream psychology.
In light of the minimal changes to the core contents of the book, I consider this edition more of an important re-release than a major revision. None the less, this revised edition is an essential book to have if one plans to use verbal protocol methodologies.