The Scientific Method

What is the Scientific Method?

It is a series of steps that help to answer some of life’s questions.

The 5 Steps of the Scientific Method:

1. Question

2. Hypothesis

3. Experiment

4. Collect Data

5. Conclusion

Step 1: Question

• What it is that you are trying to find out about.

Research: Information about the ?

Example Question:

Does Brand A or Brand B laundry detergent work best for grass stains?

Step 2: Hypothesis

• An educated guess

• Put it in an “If….then…..because….” statement

Example Hypothesis:If I test Brand A versus Brand B detergent in getting out grass stains, then I believe Brand A detergent will work the best because it costs more, and when you pay more you expect a better product.

Step 3: Experiment

• Variables–Independent (test)–Dependent–Constants

• Materials• Procedure

Variables: anything that can change the results of an experiment

• Test Variable (independent variable):– the variable that will be changed by the

person• Dependent Variable:

– The variable that changes as a result of the independent variable

• Constant Variables:– the variables that will remain the same

What is the Test Variable?

What is the Test Variable?

Type of Detergent (Brand A vs. Brand B)

Constant Variables:• amount of detergent

• time in washer

• type of stain

• etc.

Materials:

• Everything that you will need to do the experiment.

What materials would you need to test this experiment?

Materials:

• washer

• detergent A and B

• grass stain

• measuring cup

• etc.

Procedure:

• Step by step how to do the experiment.

• The “Instructions” to do the experiment.

Example Procedure:

1. Purchase Brand A and Brand B laundry detergent

2. Put grass stain on 2 white clothes

3. Etc.

Step 4: Collect Data• Table

– Organizes data, makes it easy to read

• Graph

– Shows data in a visual way

Table:

% of Stain RemovedBrand Trial 1 Trial 2

A 25 30B 50 60

Graph:

0102030405060

% of Stain Removed

1stTrial

2ndTrial

Trial #

Which Detergent is Best?

Brand A

Brand B

Step 5: Conclusion

• Summarizes the results.• Was your hypothesis correct or

incorrect. Why?• Alternate hypothesis

Conclusion:After looking at the results of the experiment I have found that Brand B removed a larger percentage of the grass stain . Therefore my hypothesis is incorrect. I believe it was incorrect because I went under the presumption that items that cost more are better products. I have found

that testing products can pay off.

Acceptance of Ideas

• After conclusion, ideas are reviewed and tested by scientific community

– Peer Review • “Good idea” or “needs more work”• Filters out results, must be valid to be published

– Publications (journals, meetings, books, etc.)

– After acceptance, idea becomes theory• May change due to conflicting information

Alternate Hypothesis:

If I test Brand B with lemon scent versus Brand B without lemon scent then I believe Brand B with lemon scent will work better because lemon juice is

acidic and many acids are good cleaners.