PERTANIKA JOURNAL OF SOCIAL SCIENCES AND HUMANITIES

This research created and validated PRISMA (PRencanaan Inklusif Siswa untuk MAsa Depan), a psychological tool intended to assess lifelong career planning competencies among Indonesian secondary school students in inclusive educational environments. A cross-sectional survey gathered data from 541 students aged 15 to 18 years across various educational tracks. The original instrument had 60 questions based on Super's life-span, life-space theory, Krumboltz's learning theory of career counselling, Savickas' career construction theory, and Banks' multicultural education framework. The development process included expert judgment for face and content validity, a pilot study, and psychometric testing with Rasch analysis (Winsteps). The results showed that the psychometric performance was very good, with a person reliability of 0.96, an item reliability of 0.99, and a Cronbach's alpha of 0.96. Principal Component Analysis of Residuals validated unidimensionality, and local dependency stayed beneath critical thresholds. The four-point Likert scale functioned effectively, though the lowest category was infrequently utilised. The Wright map showed that the difficulty of the items matched the students' abilities well. However, it also showed that more difficult items were needed to test students with very advanced career planning skills. Differential Item Functioning (DIF) analysis revealed that the majority of items operated comparably across gender and age demographics, exhibiting negligible bias. In general, PRISMA is a valid, reliable, and fair tool that can help counsellors give career advice that is fair and includes everyone.