The Scientific Method

Steps to the Scientific Method (PRHEAD) State the Problem Research the Problem State the Hypothesis Experiment (Test Hypothesis) Observe and Record Data Conclusion

Step 1 - State the Problem In your own words, describe what you want to find out. –Ex: Which car oil will allow my car to get the best gas mileage.

Step 2 – Research the Problem In order to make an educated guess (hypothesis), you need to find out more information about the problem you are trying to solve. –Ex: research various oils and their properties.

Step 3 – State the Hypothesis Make an educated guess about the solution to your problem based on your research. This is done with an “if / then” statement.. –If I use Havoline car oil then my Lamborghini Diablo will get better gas mileage.

Step 4 – Experiment This is done to test the hypothesis. Design an experiment that will provide data to prove or disprove your hypothesis. –Ex:Test four different car oils found during research

Parts of an Experiment Controlled Variable– The part of an experiment that does not change. Held constant. (same car, driven at same time for a month, same amount of oil) Independent Variable – The part of an experiment that you change. (car oil) Dependant Variable- What you are recording/observing. It changes according to how the independent variable changes.(gas milieage) –ONLY test one variable at a time.

Step 5 – Observation Observations are recorded facts about what you see during the experiment. –Graph: IV’s go on the x-axis DV’s go on y-axis

Types of Observations Quantitative – Results are numerical and have a unit. (ex: 5 meters, 45 seconds) Qualitative – Results are descriptive. (ex: the litmus paper turned red)

Observation or Inference Observation - See with own eyes (ex; the apple is red, it is raining outside, the window is 6ft long Inference: What you think might be true but not sure. (ex: She is wiping her eyes, she is crying, He has hair on his shirt, he owns a cat)

Step 6 - CONCLUSION This is a brief statement about the results of the experiment. In the conclusion state if the hypothesis was correct (proved) or incorrect (disproved). Claim, evidence, reasoning