Longitudinal Well-Being Study

The Flourishing Scale (Diener et al., 2009) is an 8-item measure of psychological well-being. Respondents rate items from 1 ("Strongly disagree") to 7 ("Strongly agree"), yielding a total score range from 8 to 56. Higher scores indicate greater well-being and flourishing.

The PHQ-8 is an 8-item measure assessing depression severity over the past two weeks. Each item scores from 0 ("not at all") to 3 ("nearly every day"), with total scores from 0 to 24. Higher scores indicate greater depression severity.

The GAD-7 (Generalized Anxiety Disorder-7) is a 7-item measure assessing anxiety severity. Each item is rated from 0 ("not at all") to 3 ("nearly every day"), with total scores ranging from 0 to 21. Higher scores indicate greater anxiety severity.

The PSS-4 (Perceived Stress Scale-4) is a 4-item measure of perceived stress, rated from 0 ("never") to 4 ("very often"). Scores range from 0 to 16, with higher scores indicating greater stress.

The Subcomponents of Affect Scale (SAS) is an 18-item measure of affect, divided into nine positive and nine negative adjectives. Positive subscales include calm, well-being, and vigor, while negative subscales include depression, anxiety, and anger. Participants rate each adjective from 0 (not at all accurate) to 4 (extremely accurate) based on their feelings over the past two weeks. Total scores for positive and negative affect are summed from their subscales.

The Brief Resilience Scale (BRS; Smith et al., 2008) is a 6-item measure of stress recovery, rated from 1 (strongly disagree) to 5 (strongly agree). Higher scores indicate a stronger ability to "bounce back" after setbacks.

The UCLA 3-Item Loneliness Scale is a brief measure assessing subjective feelings of loneliness and social isolation. Participants rate each item on a 3-point scale, from 1 (hardly ever) to 3 (often), with higher scores indicating greater loneliness.

The Sense of Social Fit Scale (Walton & Cohen, 2007) measures students' perceived belonging within their school environment. For our purposes, we used a shortened version with two items: "I fit in well at my school" and "Other people understand more than I do about what is going on at my school," rated on a 5-point scale from 1 (strongly disagree) to 5 (strongly agree).

The Perceived Cohesion Scale (Bollen & Hoyle, 1990) measures a sense of belonging and morale within a community using a Likert scale from 0 (strongly disagree) to 10 (strongly agree). For our purposes, we use a single-item version: "I see myself as part of the campus community."

This measure, adapted from the Working Alliance Inventory - Short Revised (WAI-SR), assesses participants' expectations and experiences with chatbots. Participants rate anticipated and actual interactions across three areas-Goal, Task, and Bond-on a 5-point scale from 1 (seldom) to 5 (always), with higher scores indicating stronger alignment.

The Multi-Dimensional Measure of Trust (MDMT; Ullman & Malle, 2023) assesses perceived trustworthiness of the Flourish chatbot, Sunnie, through a set of 10 attributes (Form A), rated from 0 (Not at all) to 5 (Very), with a 'Does Not Fit' option. Only participants in the Flourish app condition complete this measure.

The Academic Self-Efficacy scale (van Zyl et al., 2022) measures students' confidence in their ability to succeed academically. Participants rate their agreement with statements such as "I generally manage to solve difficult academic problems if I try hard enough" on a 5-point scale, from 1 (strongly disagree) to 5 (strongly agree). Higher scores indicate greater self-belief in tackling academic challenges and achieving study-related goals.

School perceptions are measured using two single-item measures from the Healthy Minds Survey, along with an adapted Inclusion of Other in the Self (IOS) scale to capture closeness to the university.

The first item rates agreement with the statement, "At my school, students' mental and emotional well-being is a priority," on a scale from 1 (strongly agree) to 6 (strongly disagree).

The second item rates satisfaction with the overall school experience from 1 (very dissatisfied) to 6 (very satisfied).

For university closeness, participants select one image from a series of overlapping circles that best represents their relationship with the university, with greater overlap indicating a stronger connection.