In this paper we describe an exploratory study on the use of a structured interviewing evaluation technique with 6 to 8 year old children. The study examines whether children are able to answer the post-task questions referring to the various interaction stages (planning, translation and assessment), and whether the technique does not lead to adverse effects such as finding a different set of interaction difficulties. The results show that children overall are fairly good at answering the questions, but have most trouble answering the planning question. Furthermore, the negative side-effects of applying the technique on the outcome of the usability test are minor. Overall, we advise practitioners to apply such a technique to uncover extra data about possible causes for interaction difficulties and to optimize the effort by only asking detailed questions about those parts of the design that need extra attention.