This report documents an exploration of the relationship between think aloud and constructive interaction when involving children as subjects, and how this relates to the number of experienced usability problems. Furthermore it documents how the gender and level of acquaintance of the subjects affect this relationship. This exploration is done through an experiment involving 60 children testing in 6 different compositions, resulting in a list of usability problems, along with the time used and the results of a NASA TLX-test, revealing the mental workload. The analysis of these results showed that both gender and level of acquaintance influences the outcome of a usability test and that constructive interaction yields the highest number of usability problems with virtually no difference in time used to complete the task.