Structural validity of ESM items measuring momentary social experience in adolescents

Valid daily‑life measures of social experiences are essential for (adolescent) mental health research. This study examines the structural validity of scales measuring daily-life social experiences, namely the quality of social company, online company, in-person solitude, and online solitude, using multilevel confirmatory factor analysis on N = 1,913 adolescents. We tested measurement invariance across groups based on sex, age, and a clinical characteristic relevant to social interaction and solitude: lifetime history of self-harm. Results indicated structural validity of scales measuring the quality of social company, the quality of online company, and the quality of in-person solitude in the whole sample. However, measurement invariance testing revealed non-invariance of the scales across some of the tested groups. Further conceptual work on these constructs and a thorough development of relevant, non-invariant scales is imperative.