Test understanding of how material choice (e.g., wood, paper, plastic), shape (beam, arch, truss), and size (length, width, thickness) affect the strength of a simple bridge model; students should predict and explain performance differences using basic ideas of load, tension and compression, interpret simple test results (how much weight the model holds and where it fails), and suggest design changes to improve strength. Suitable for Grades 3–5; medium difficulty requiring observation, comparison, and reasoning.