Self-generated explanations on the question demands are not always helpful.

This study had two main purposes. First, to measure high-school students' task model representation under the instruction to self-explain questions; second, to test the effects of self-generated explanations on task-demands understanding and performance on questions. We designed a simple experimental situation where high-school students were asked to read two texts and answer questions. Only in half of the questions students were required to self-explain with their own words what the question was asking them for before answering. Contrary to our expectations, self-explaining the questions did not significantly affect skilled comprehenders, whereas it hindered performance in less-skilled comprehenders. Moreover, it inhibited their active engagement in search for textual units of information. Less-skilled comprehenders' explanation protocols included inaccuracies, with consequences on the search process and success in the task. The relationship among quality of task model, search for information and success is discussed in light of the TRACE model (Rouet, 2006).