AP Biology - Unit 0: Biology Review

pg. 8 - 15

Hypothesis Testing

Statistical tests used to test a hypothesis about a population using a sample.

Null Hypothesis

Hypothesis that claims there will be no affect on the dependent variable from the experiment. There will be no difference between the two groups of data.

Alternative Hypothesis

There is a relationship between the two groups of data due to a non-random cause.

Null Hypothesis is used as…

a baseline to compare experiment results to.

Control Group

Used to compare to the experimental group to help validate statistical analysis.

Experimental Group

Where the independent variable (IV) is manipulated to observe its effect on the dependent variable (DV).

Constant Variable

A variable that remains unchanged throughout an experiment to ensure that only the manipulation of the independent variable resulted in the test outcome.

Dependent Variable (Y-AXIS)

A factor that is measured and affected by the manipulation of the independent variable.

Independent Variable (X-AXIS)

One factor that is manipulated in order to observe it's effect on the dependent variable.

Negative Control Group

Group that is not given a treatment OR is given a treatment that is known to have no effect to ensure no effect occurs where it shouldn't.

Positive Control Group

Group that is given a treatment that is known to have an expected effect as a reference point to what an effect looks like.

Results of an experiment either _______ or _______ the hypothesis.

support, refute

A null hypothesis will always include the wording _______ or _______.

no effect, no difference