Experimental Procedure Science Fair Recipe

Following the Scientific Method, you have selected a topic or developed a question; gathered information about the topic or to answer the question; formed a hypothesis, or a guess of what will happen.  Now it’s time to create an experimental procedure.  The procedure is a step-by-step plan or recipe describing how to perform the experiment. 

Tip 1: Be detailed as you write down your steps so that anyone else can follow what you are doing and replicate your experiment. AS you work, you can add pictures or diagrams and photos to make the directions clearer.

Tip 2: Create a Materials List with details about what equipment and supplies you are using in the experiment.  Be sure to include details such as the size of a measuring device, the amount of a liquid, and so on.  Remember to mention items like electricity, refrigeration, special lights, or heat.

Tip 3: Use the metric system to express sizes and amounts.  Measure, for example, in millimeters or centimeters, grams and kilograms, or other metric measurements.  You may need to use special measuring devices marked with metric measurements. 

Tip 4: Write the steps in your log and keep it handy as you begin the experiment in case you realize you need to add a step or details to the procedure.

Tip 5: Identify the variables and controls in your experiment.  Variables are any factors which may affect the experiment or alter the outcome.  Controls are the factors that will not change during the experiment.  You will test the experimental group and compare it to the control group during the procedure. 

Tip 6: Decide how many times you will conduct your experiment. When you repeat an experiment, this is called a “run.” Repeat the procedure exactly as you have written it down each time to be certain it works and you have been consistent in performing the experiment the same way each time. 

Tip 7: Describe also what you do between runs.  How do you store the materials, the control group and experimental group between runs?  Are there are variable factors affecting the experimental and control group between runs?

Tip 8: Record the results of each run in your log for later use in data analysis.

Tip 9: Copy the step-by-step procedure exactly as you wrote it in your logbook for your research paper, and your display or backboard. 

Tip 10: Include safety precautions in your procedure.  Do you need gloves, goggles, any special method for disposing of your materials when the experiment is completed?  How you handle the disposal of the project materials can be very important.

The experimental procedure allows others to follow your work step-by-step and helps to keep you on track as you perform your experiment.  With these tips, you can create an experimental procedure.