Children's performance on ground rules questions: implications for forensic interviewing

Ground rules, also called interview instructions, are included in investigative interviews with children around the world. These rules aim to manage the expectations of children who are typically unaccustomed to being questioned by adults who are naïve to the children's experiences. Although analog research has examined the efficacy of ground rules instruction, a systematic analysis of children's ability to respond appropriately to each of the rules has not been reported. In the current study, we scored the accuracy of children's (N = 501, 4 to 12 years) responses to 5 ground rules practice questions (e.g., "What is my dog's name?") and 2 questions that asked whether they would follow the rules, and then assigned inaccurate responses to 1 of several error categories. Few children answered every question correctly, but their performance on individual questions was encouraging. As expected, there were marked differences in children's understanding across ground rules questions (especially among the younger children), with "Don't guess" and "Tell the truth" rules being the easiest to comprehend. Together with evidence that ground rules instruction takes little time to deliver (typically 2 to 4 min) and is associated with improved accuracy in previous research, these findings support the use of ground rules in investigative interviews of children 4 years and older.