Ericsson training

There are several issues that need to be considered about the validity of using verbal reports as data and inferring thought processes from them. Ericsson and Simon [1984] address these concerns by demonstrating how verbal protocols are distinct from retrospective responses and classic introspection by trained observers and detailing the methods for collecting and analyzing protocols. 

Ericsson B, Haeger K, Lindell SE. Effect of physical training on intermittent claudication. Angiology 1970 21 188-192. 

---