Mark was doing a piece of research on young people and crime. He wanted to know how in certain youth cultures it seemed acceptable to take part in some minor criminal acts. He spent a long time with three groups, participating in shopping trips, spending the weekend and generally 'hanging about', and came to understand the youth cultures from their own perspective. When he began a thorough sorting of his data after fieldwork had finished he began to notice a pattern that he hadn't during fieldwork. He noticed an important gender difference in talk about crime, criminal behaviour and attitudes to criminal acts. He was able to include some of this in his writing up, but as he had only noticed the pattern at the end of the fieldwork phase he was not able to explore it as much as he would have liked.