What's in a measure? A multi-method study of child sexual offenders' beliefs

The hypothesis that child sexual offenders (CSOs) hold distorted, offence-supportive beliefs is usually investigated using interview and questionnaire techniques. However, in light of various problems associated with the use of these techniques, researchers are increasingly turning to cognitive-experimental approaches. To date, no study has examined potential differences in the nature of the beliefs that are revealed using interview, questionnaire, and experimental methods. In this study, data is gathered using these three methods and the results triangulated. CSOs are interviewed and the content categorised into five belief types. CSOs and offender controls then complete a questionnaire measure of offence-supportive beliefs and an experimental task (Rapid Serial Visual Presentation–Modified, or RSVP-M), which uses sentence reading times to explore content held in cognitive structures. As hypothesised, CSOs showed evidence of holding distorted beliefs according to the interview and questionnaire measures. Against predictions, however, CSOs did not show evidence of holding distorted belief structures on the RSVP-M task. In fact, the three methods showed no agreement regarding the belief types each CSO was deemed to hold. These results raise important questions about the phenomena and potential artefacts measured by each method.