Online, 30-minute self-administered relationship education activity for youth ages 16-20

This measure uses 3 questions post-intervention to assess the extent to which participants gained learned something important after the activity, thought about relationships differently, or felt validated in the way that they have been thinking/acting in their relationships.

The GAD-7 measures the severity of clinical anxiety symptoms, based on diagnostic criteria for generalized anxiety disorder. The GAD-7 includes 7 items asking respondents how often, during the last 2 weeks, they were bothered by each of 7 anxiety symptoms. Higher scores reflect higher generalized anxiety symptoms.

The Relationship Deciding Scale measures effective decision-making during interpersonal situations. It has three subscales with items rated on a 5- point scale (1 = strongly disagree, 5 = strongly agree), relationship confidence, assessing confidence in maintaining a relationship; warning signs, assessing awareness of and ability to deal with warning signs in relationships; and deciding, assessing thoughtfulness regarding decisions. Higher scores suggest more effective decision-making.

This measure consists of 21 items, rated 1-7 (1 = strongly disagree, 7 = strongly agree), and measures six domains: (1) confidence in one's knowledge about what a healthy relationship is and ability to manage relationships; (2) confidence in one's knowledge about and ability to cope with relationship problems; (3) willingness to compromise oneself; (4) beliefs that any relationship can work if you work hard enough; and (5) overreliance on emotions for relationship decisions. Higher scores reflect better relationship knowledge and efficacy.

Immediately after the activity, participants will be asked, "In your opinion, what was the most important thing you learned from this activity?" "Based on what you learned, will you do anything differently in your relationships? If yes, please elaborate on what you will do differently." At the 3-month follow-up, we also ask two additional questions, "From what you remember, what was the most important thing you learned in our relationship education activity?" and "Since completing this activity, have you noticed any changes in how you navigate your relationships? If yes, please tell us what you have noticed." Participants are provided with space to answer these questions via text entry.

The PFS asks youth to rate agreement with 7 statements indicating perceived acceptability of an SSI (e.g. "I enjoyed the program") on a 5-point Likert scale (1="really disagree"; 5="totally agree"). A score of 3.5/5 or above on any given PFS item is interpreted as an "acceptable" rating on that item. Scores are calculated at the item-level, and higher scores reflect greater acceptability for each item.

The Relationship Structures Questionnaire is a self-report measure that assesses general attachment patterns across a variety of close relationships. It asks participants to rate the extent to which each statement describes their feelings about close relationships in general. This abbreviated measure consists of 9 items, ranking from 1 (Strongly Disagree) to 7 (Strongly Agree). This measure consists of two subscales: anxiety and avoidance. Higher scores on the anxiety and avoidance subscales represent higher levels of attachment insecurity.

We assessed empathy and perspective-taking with the two subscales of the Interpersonal Reactivity Index (IRIC; Péloquin & Lafontaine; 2010); this measure was only administered to youth who were dating or in a committed romantic relationship. Items rated on a 5-point scale (0 = does not describe me well, 4 = describes me very well). Example items for perspective taking include, "When I'm upset at my partner, I usually try to 'put myself in his/her shoes' for a while" and empathic concern, " I often have tender, concerned feelings for my partner when he/she is less fortunate than me." Participants were instructed to 'Answer about your current or most recent partner,' and higher scores reflect higher levels of empathy and perspective-taking, respectively.

We used the 4-item measure from the Couple Satisfaction Index to measure relationship satisfaction; this measure was administered to youth who were dating or in a committed romantic relationship. Items include questions like "How rewarding is your relationship with your partner?" and "In general, how satisfied are you with your relationship?" Items are ranked 0- Not at all to 5- Completely. CSI-4 scores can range from 0 to 21. Higher scores indicate higher levels of relationship satisfaction.