OBJECTIVE: This study compared the effects of open-ended versus specific questions, and various types of open-ended questions, in eliciting story-grammar detail in child abuse interviews. METHODS: The sample included 34 police interviews with child witnesses aged 5-15 years (M age=9 years, 9 months). The interviewers' questions and their relative sub-types were classified according to definitions reported in the child interview training literature. The children's responses were classified according to the proportion of story grammar and the prevalence of individual story grammar elements as defined by Stein and Glenn (1979). RESULTS: Open-ended questions were more effective at eliciting story grammar than specific questions. This finding was revealed across three age groups, two interview phases and irrespective of how question effectiveness was measured. However, not all types of open-ended questions were equally effective. Open-ended questions that encouraged a broad response, or asked the child to elaborate on a part of their account, elicited more story-grammar detail compared to open-ended questions that requested clarification of concepts or descriptions of the next (or another) activity or detail within a sequence. CONCLUSIONS: This study demonstrates that children's ability to provide story-grammar detail is maximised when there is minimal prompting from the interviewer. PRACTICAL IMPLICATIONS: Given the association between story grammar production and victim credibility, greater guidance is warranted in interviewer training programs in relation to the effects and administration of different types of open-ended questions.