Interdisciplinary Project-Based Learning and Academic Achievement in Secondary School: A Quasi-Experimental Study across English, Science, and Social Studies in Chennai

Abstract

Project-based learning (PBL) is a multidisciplinary pedagogical approach inwhich students undertake sustained, inquiry-driven projects that requireintegrating knowledge and skills from multiple subject areas to address ameaningful driving question. While single-subject PBL has been extensivelyevaluated, evidence on interdisciplinary PBL that deliberately connectscurriculum content across three or more subjects within a shared projectframework, and its effect on academic achievement in each contributingsubject, is comparatively limited in the Indian school context. This studyemploys a quasi-experimental pre-test/post-test design comparing 90 Class 9 students in an interdisciplinary PBL section — integrating English, Science,and Social Studies through a 16-week environmental sustainability project — against 90 matched students in conventional subject-siloed instruction. Post-test achievement scores were significantly higher in the PBL group across all three subjects: English (+10.6 pp, p < 0.001), Science (+11.6 pp, p < 0.001), and Social Studies (+14.2 pp, p < 0.001) relative to the comparison group, with the largest between-group differences on application and synthesis test items rather than recall items. Student self-reported learning motivation and collaboration skill ratings were also significantly higher in the PBL group. These findings support the adoption of interdisciplinary PBL as a school practice with demonstrable multi-subject academic benefit in secondary education.  KEYWORDS: Project-based learning, Interdisciplinary education, Secondaryschool, Academic achievement, Multidisciplinary pedagogy, PBL, Schoolpractices, Chennai, Inquiry-based learning