From Interface to Volition: Evaluating a HAPA-Based Persuasive Ecosystem for Children’s Oral Health Readiness

Effective pediatric oral health interventions require functional tools and psychological support to bridge the gap between intention and action. However, persuasive technologies often lack links between features and behavior change mechanisms. Grounded in the Health Action Process Approach (HAPA) and Persuasive Systems Design (PSD), this study evaluated a theory-driven eHealth ecosystem for oral care. We used a within-subject experiment with school-age children to compare the proposed system with a product and examine its immediate psychological determinants. Results showed the theory-driven system outperformed the control, activating action self-efficacy, intention, and planning constructs—“immediate cognitive readiness.” Under the age-stage grouping and testing arrangement, older children showed larger planning gains, especially coping planning gains, than younger children. By validating the “design-mechanism” alignment, this study links features with volitional processes. The findings offer a framework for auditing early stage eHealth effectiveness beyond engagement metrics to the verifiable psychological impact.