Verbalisation of processes underlying prospective memory.

Although prospective memory (PM) has been studied extensively, relatively little research has addressed errors in different steps of PM performance. The aim of this study was to examine errors occurring in different phases of the microstructure model in PM performance and whether verbalisation can serve in their measurement. We report the results of two experiments in which young adults were divided into experimental and control groups. Both groups solved either a 3-day (Experiment 1) or a 5-day (Experiment 2) version of the Virtual week (VW) task. Experimental groups had to verbalise each PM task before performing it. The results of Experiment 1 showed that verbalisation may prolong the time to execute the task, but in both experiments, verbalisation did not affect the PM performance. In analysing different types of errors, we found that: (1) prospective component errors are more often caused by tasks requiring greater strategic monitoring (only Experiment 1), (2) recall component errors are evident in irregular tasks, and (3) execution errors are more often evidenced in tasks with greater response competition. This confirms that there is a wide range of processes that can lead to PM failures, and verbalisation is one method by which we can detect them.