2.3.1. Knowledge about NSSI
NSSI
At each time point, participants were presented with 16 true or false questions about NSSI that were based on the course content. They were asked to respond with “Disagree”, “Agree”, or “Don’t know” (the latter was coded as an incorrect response). Knowledge scores were calculated as the percentage of correct answers (possible range: 0–100), and mastery of knowledge was set at 80%, consistent with previous evaluations [