From Pendulums to Smartphones: Instructional Approaches for Measuring Local G and Developing Uncertainty Reasoning in Preservice Teachers

Preservice science teachers need opportunities not only to conduct laboratory investigations but also to learn how to transform them into inquiry-based instruction. This theoretical synthesis examines investigations of local gravitational acceleration (g) as a context for developing the knowledge and practices required to teach scientific inquiry. Drawing on research concerning practical work, scientific modeling, and evidence-based explanation in science teacher education, we analyze pendulum, free-fall, inclined-plane, projectile-motion, Atwood-machine, and technology-supported investigations. The analysis uses a four-stage framework in which preservice teachers (1) experience an investigation as learners, (2) examine its conceptual and methodological demands, (3) redesign it for school science, and (4) rehearse and reflect on its instruction. Across the methods, preservice teachers construct and revise measurement models, evaluate uncertainty and systematic bias, calibrate and validate instruments, and justify claims using evidence. They also identify likely student difficulties, select appropriate scaffolds, adapt equipment to classroom constraints, and design assessments of scientific reasoning. Sources of uncertainty such as timing offsets, air resistance, friction, alignment, finite-amplitude effects, and instrument resolution are treated as resources for teaching how evidence, models, and measurement decisions interact. Classical methods are considered alongside electronic timers, optical sensors, microcontrollers, video analysis, and smartphones. The synthesis proposes design principles and assessable teacher-learning products for face-to-face, remote, and hybrid settings. Rather than presenting gravity experiments as activities for students generally, the article positions them as structured experiences through which preservice teachers learn to plan, facilitate, and assess inquiry-based science instruction.