Students are asked to design a "test" to learn more about which factors are important for germination and seedling growth. We help students design experiments, guiding the class toward an understanding of variables that should be considered and helping students see the need for a control or comparison condition. For example, could we test whether seeds will grow if they get no light at all? As different experiments are proposed, the class is encouraged to evaluate each proposal, "What will we know if we do it that way? Would that be a good test?" We model setting up contrasts and comparisons. Designing and carrying out a class experiment to determine whether seeds will grow in the dark provides a framework for future studies. Later, small groups plan investigations based on other seed questions.
