This study investigated the usefulness of a computer program designed to assess young children's understanding of words that may be relevant to an investigative interview about assault. Forty‐one police officers conducted two interviews with five‐ to six‐year‐old children (one was conducted with the program and one without). The program's effectiveness was based on the interviewers' ratings of the usefulness of the program as well as three independent indices of interviewer–child rapport. Overall, the police officers perceived the program to be an extremely useful pre‐interview assessment. However, the program had little impact on the officers' style of questioning and the nature of the children's responses. The implications of these findings are discussed.