The Impact of School-Based Career Activities on Vietnamese Lower Secondary Schools Students’ Career Decision-Making Self-Efficacy

Grounded in Social Cognitive Career Theory (SCCT), this study investigates the relationships among school-based career guidance activities, perceived effectiveness (PE), and Career Decision-Making Self-Efficacy (CDMSE) among lower secondary school students (Grades 6–9) in Vietnam. The research disaggregates career interventions into three distinct dimensions: informational, interactive (INT), and experiential (EXP) activities. A quantitative survey was conducted with a stratified cluster sample of 4,910 lower secondary school students across seven representative provinces in Northern, Central, and Southern Vietnam, analyzed via partial least squares structural equation modeling (PLS-SEM) and multi-group analysis (PLS-MGA). The structural model revealed that school-based activities do not automatically enhance psychological confidence. Instead, Perceived Effectiveness (PE) emerged as a substantial mediator, explaining 61.4% of the variance in CDMSE (R2 = 0.614). Informational activities exerted the highest total indirect effect, serving as an indispensable cognitive foundation to reduce vocational ambiguity. Concurrently, interactive (? = 0.101) and experiential (? = 0.095) activities demonstrated significant positive direct paths to PE. Notably, while the experiential dimension yielded a negligible direct path to CDMSE (? = 0.024, p = 0.021), its impact was driven heavily by a potent indirect path (? = 0.073, t = 5.714) filtered through PE. This underscores that raw exposure to reality loses its psychological value unless tightly coupled with intentional teacher scaffolding (pre-activity preparation and post-activity reflection). Furthermore, PLS-MGA established structural invariance across classroom tracking environments (regular vs. selective classes). These findings offer vital empirical insights for educational administrators to optimize resources and transition toward highly interactive, well-scaffolded guidance models within Vietnam's 2018 General Education Curriculum.