Scientific Method

Steps of the Scientific Method

Question

Research

Hypothesis

Analysis ConclusionInvestigation/ Experiment

Scientific Method

1. Starts with a QUESTION– How do I make a PB & J sandwich?

2. HYPOTHESIS—educated prediction of the outcome– Always in the form of a specific statement

(complete sentence)– I believe that these are the steps to making a

PB & J: (1) take two pieces of bread from the bag, (2) etc.

Scientific Method (ctd.)

3. EXPERIMENT—test your hypothesis– Try to make a PB & J using the directions in your

hypothesis

4. ANALYSIS—look at the data that you gathered and decide what that data means– Could you make a PB & J using your instructions?

5. CONCLUSION—was your hypothesis correct?– If not, use the information you gathered to construct a

new hypothesis and conduct a new experiment

Using the Scientific Method

• QUESTION

• HYPOTHESIS

• EXPERIMENT

• ANALYSIS

• CONCLUSION

Vocabulary

Experiment: artificial situation in which the investigator controls the factors that could affect the outcome

Variable: the factor that might affect the outcome

Control: the factor that has NO affect on the outcome and is only used for comparison during an experiment

Kinds of VariablesINDEPENDENT

• Controlled by the experimenter

CONTROL VARIABLE• The experimenter makes

a special effort to keep other factors constant so that they will not effect the outcome.

• Those factors are called control variables.

DEPENDENT

• Responds to and measures changes in the independent variable.

Collect / Organize Data

Once you collect data, you need to organize it into a data table and/ or a graph.

Independent Variable

Dep

end

ent

Var

iab

le

Identifying Variables

Situation: You are investigating the body temperature of a frog at different times of day. You decide to take a temperature reading in the morning, at noon, at night, and midnight.

• Independent variable is….time because you are controlling the times it is being collected.

• Dependent variable is . . . The frog’s body temperature. You have no control over the frog’s body temperature; you are simply observing it.

Setting Up a Controlled Experiment

• What is the QUESTION?

• HYPOTHESIS

• Identify the INDEPENDENT VARIABLE(S)

• Identify the DEPENDENT VARIABLE

• Identify the CONTROL

• How will you collect data

Controlled Experiments

You have been asked to test the effectiveness of a new waterproof

mascara

• Control?

• Independent variable?

• Dependent variable?

You have been asked to test the effectiveness of a new teeth whitener

• Control?

• Independent variable?

• Dependent variable?

You have been asked to test the effectiveness of a new fuel additive.

• Control?

• Independent variable?

• Dependent variable?