Write a hypothesis or prediction that is testable. A prediction is testable if the scientist can design an experiment and postulate a measurable outcome.
Format the prediction or hypothesis in an "if and then" statement. This format sets the requirement and conditions for an expected outcome to take place. For example, if temperature exposure affects the growth rate of pea plants, then cold temperatures will stunt the growth of pea plants.
Establish dependent and independent variables in the hypothesis. For example, if temperature exposure affects the growth rate of pea plants, then cold temperatures will stunt the growth of pea plants. The independent variable is what is changed in the experiment. In this case the different cold temperatures is the independent variable. The dependent variable is what is measured. The growth rate of the pea plants is the dependent variable. Both variables provide measurable outcomes to either prove or disprove the hypothesis.