“It’s Tricky”: Evaluating the Effectiveness of One vs. Many Ground Rule Instructions With Child Witnesses

Interviews with children about suspected child maltreatment typically begin with pre-interview instructions known as ground rules, intended to establish the conversational expectations and assist children with signalling when questions are difficult or cannot be answered. However, previous research has revealed that ground rules do not consistently lead to their intended outcome. Some researchers have suggested that the format of ground rules are not appropriate for children’s cognitive, social, and linguistic competencies. The purpose of the current study was to evaluate a novel streamlined ground rule format, designed to minimise cognitive load on children and allow them to use their own language to signal when questions were problematic. Interviews were held with 129 5-12 year-old children. Half received the novel singular streamlined ground rule instruction, and the other half received instruction about three ground rules, modelled on the forensic interview protocol used with children in Aotearoa New Zealand. A repeated measures ANCOVA revealed that children were more able to use the streamlined ground rule than multiple discrete rules when the matching of their response to the ground rule question was used (e.g., responding “I don’t understand” to an incomprehensible question). When we adopted a more liberal scoring criteria, allowing for any kind of response that signalled difficulty with the question (e.g., shrugging in response to an incomprehensible question) both groups of children were equivalent. Both analyses suggest that children are unlikely to adopt the response format trained by using multiple specific rules, and that a “one rule” approach may be just as useful.