Students are allowed one week to do the experiment. The PBA is essentially a lab practicum , a crucial element in the Modeling Method of Instruction . In the Modeling Method, each modeling cycle starts with a paradigm lab in which teams of students design an experiment to answer a question about nature. The teacher guides students to identify the independent and dependent variables, and to use multiple representations such as graphs, motion maps and system schema to derive a mathematical model. Through classroom discourse which includes extensive Socratic questioning, misconceptions are clarified and consensus is reached on the model.
Students deploy the model to solve real-world problems, often by a lab practicum .
Since the PBA employs aspects of the modeling cycle, students of modeling teachers earn high scores on PBAs. PBAs promote reform by requiring non-modelers to apply effective strategies of the modeling cycle in their classroom instruction. They serve also to motivate teachers to participate in modeling workshops. Their poor results motivated him to learn the Modeling Method. Measuring the acceleration of gravity, g, for 5 different masses.