Scientific enquiry is a creative process, commonly beginning with a question or problem, then generating a tentative answer or solution, and testing it. In the classroom, the question, perhaps in the form of a problem, is generally given, ready-made, to students by the teachers. With the aim of providing young students with a fuller experience of the scientific process, and wanting the potential of self-generated questions for interest and motivation, we explored various ways of inducing children (8-11 years, and of various sample sizes) to ask questions in science. Question-asking was found to be complex, involving the construction and articulation of descriptive and causal mental models of situations. We suggest several factors which influence and order the process, especially the situation or stimulus, the teaching and learning environment, and the attributes of the child. It takes time to produce questions which could lead to scientific enquiry, and it needs teaching skill to provide efficient and effective opportunities for children to ask questions, and help them put them into a suitable form. Question-asking seems worthy of further study.