Statistics and Experimental Design Vocab

Hypothesis

A tentative explanation that needs further investigation.

Null Hypothesis

• H₀

• Assumes everything is equal

• If the (INDEPENDENT VARIABLE) changes then there is no significant difference between the (DEPENDENT VARIABLE/RESULTS).

Alternative Hypothesis

• H₁

• Assumes the results will be significantly different from one another

• If (INDEPENDENT VARIABLE), then (DEPENDENT VARIABLE).

Independent Variable

The variable that is being changed or altered in an experiment.

Dependent Variable

The variable that changes in an experiment as a result of the Independent Variable's alteration.

Experimental Group

The setups in the experiment with unknown results. What we are really interested in testing.

Constant/Controlled Variable

Factors that the experimenter attempts to keep the same in every group (including the control group).

Control Group

The standard of comparison in an experiment.

Positive Control Group

The group exposed to a treatment that is known to produce the measured/desired effect. (Should have a KNOWN significant EFFECT)

Negative Control Group

The setup that is not exposed to any treatment that is expected to cause a change in the desired/measured effect. (NO EFFECT or no change from NORMAL)

Variance

How spread out the data is form the mean (average).

Standard Deviation

A measure of how spread out the data is form the mean (variance).

Standard Error of Mean

A measure of how well the sample mean represents the true population mean.

Correlation

The relationship between two variables.

Mean/Average

A single, representative value for a set of data.

Equidistant

Objects or points that are the same distance apart.