Creation and validation of the pictorial ecological momentary well-being instrument (EMOWI) for adolescents

PURPOSE: Adolescence is characterized by the ongoing maturation of emotion-regulation skills and increased emotional reactivity. There is a need for a measurement tool suitable to the Ecological Momentary Assessment methodology, to better capture within-day variations in well-being, and provide fine-grained data that can help understand how environments, behaviors, and health intersect. This paper presents the development and evaluation of the Ecological MOmentary Well-Being Instrument for adolescents, designed for use in EMA. METHODS: A mixed-methods study was conducted, using both qualitative and quantitative approaches, to develop and assess the EMOWI. A literature review, pictorial production by graphic designers, and qualitative interviews with French and Canadian professionals and adolescents helped design and evaluate the scale face validity. Quantitative evaluation of dimensionality, reliability, and validity was conducted in two samples of French 8th graders. RESULTS: The resulting 8-item EMOWI showed excellent face validity. Confirmatory factor analysis supported a single factor hypothesis (RMSEA = 0.072). Internal consistency (Cronbach’s alpha = 0.85) and intraday test–retest reliability (ICC = 0.83) were high. Correlations with existing scales were consistent with preset hypotheses. Ceiling effects were evidenced for all items, yet not on the global score. Quantitative estimations were similar for the verbal and pictorial versions, but qualitative findings argued in favor of the pictorial version. CONCLUSION: The 8-item pictorial EMOWI is a short and innovative instrument to measure momentary well-being in adolescents aged 12 to 17 years. Its strong psychometric properties and its acceptability among adolescents make it an excellent candidate instrument for the Ecological Momentary Assessment of well-being in this population. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11136-021-03077-9.