Perhaps a scientist has observed that plants that receive fertilizer grow taller than plants that do not. Once you state a hypothesis, you probably want to find out whether or not it explains an event or an observation. This requires a test. A hypothesis must be something you can test. To test a hypothesis, you design and carry out an experiment.
Experiments involve planning and materials.
Let's figure out how to conduct an experiment to test the hypothesis stated before about the effects of fertilizer on plants. First, you need to write out a procedure. A procedure is the plan that you follow in your experiment. A procedure tells you what materials to use and how to use them. You will water the five bean plants in Group A with 200 mL of plain water and no fertilizer twice a week for three weeks.