<p>The use of analogies as reasoning tools that play a key role in human cognition at all ages has been of interest to educators, scientists, and philosophers ever since Aristotle. Indeed, research has consistently found that analogies provided by teachers can, and do, play an important role in facilitating student understanding of scientific ideas. Despite the effectiveness of teacher provided analogies little research has been undertaken on the use, and effectiveness, of student self-generated analogies in helping them to understand novel situations. This article reports on a cross-age study of student prediction-making in novel situations that investigated the basis and justification that students provided when asked to make predictions about novel situations. The study investigated whether they self-generated analogies (SGAs) in order to make their predictions and, in particular, whether such predictions and justifications were based on their use of SGAs.</p>