The <em>Art Nouveau Path</em>: Longitudinal Analysis of Students’ Perceptions of Sustainability Competence Development through a Mobile Augmented Reality Game

This paper presents a repeated cross-sectional longitudinal (trend) analysis of students’ self-perceived sustainability competence development across three waves surrounding participation in the Art Nouveau Path, a heritage-based mobile augmented reality game designed to foster sustainability competences, located in Aveiro, Portugal. In total, 1,094 questionnaires were collected using a GreenComp-grounded instrument adapted from the GreenComp-based Questionnaire (GCQuest) to this context (25 items; 6-point Likert). Data were gathered at three stages: baseline (S1-PRE; N = 221), immediately post-intervention (S2-POST; N = 439; n = 438 retained for scale scoring after applying a predefined completeness criterion), and follow-up (S3-FU; N = 434). Because responses were anonymous, waves were treated as independent samples rather than within-student trajectories. The Embodying Sustainability Values domain score and item-level response distributions were compared across waves using ordinal-appropriate non-parametric group comparisons, effect-size estimation, and descriptive threshold indicators. Results indicate an improvement from baseline to post-intervention, followed by partial attenuation at follow-up while remaining above baseline. Mean scores increased from 3.70 (S1-PRE) to 4.64 (S2-POST) and then stabilized at 4.13 (S3-FU). These findings, while exploratory, suggest that this heritage-based augmented reality game may have enhanced perceived sustainability competences. A structured program of follow-up activities is proposed to help sustain gains.