This paper covers three main areas:eliciting teachers' views of the nature of science; interpreting and understanding these views; and developing them in the context of initial or in-service teacher education. The three areas clearly overlap but we begin with eliciting:this section includes a look at ‘past probes’, and then presents the notion of ‘critical incidents’, with a range of examples. We argue throughout that critical incidents can be used partly as a means of probing teachers' views of science, but also have value as a tool for professional development. We then discuss interpreting and understanding teachers' responses to critical incidents, based on our research with over 300 teachers and student teachers who have worked with them. In the third section, on developing, we pursue the argument that teachers' understandings of the nature of science are located in their professional experience. We argue that if teachers' understandings are embedded within their professional practice this has important consequences for appropriate teacher education and professional development in the area of the nature of science.