A Systematic Exploration of Designing Project-based Assignments for Junior High School Science: Principles, Strategies and Case Studies

With the curriculum reform oriented toward core competencies, traditional junior high school science teaching models have gradually exposed deficiencies of emphasizing theory over practice and knowledge over abilities. This paper focuses on the application of project-based assignments in junior high school science teaching, systematically reviews their theoretical foundations, research progress, advantages and challenges. It proposes a design framework and implementation strategies based on principles of inspiration, comprehensiveness, and authenticity. Through case analysis, this paper uses “unveiling the secrets of combustion—home kitchen fire safety action” as a theme to demonstrate how project-based assignments cultivate students’ scientific inquiry abilities, innovative thinking, and social responsibility through driving questions, task chain design, interdisciplinary integration, and diversified evaluation systems. Research shows that project-based assignments can effectively enhance students’ learning interest and comprehensive abilities, but their implementation still faces challenges in terms of time, resources, and evaluation. This paper provides educators with operational design strategies and practical pathways, and offers suggestions for future research directions.