Null Hypothesis Testing

Research Methods — Week 12. From the comprehensive notes.

What is a null hypothesis?

A specified population claim, often no relationship or no difference, evaluated against the data.

What is an alternative hypothesis?

The competing claim that a population relationship or difference exists.

What does a p-value represent?

Under the null hypothesis and model assumptions, the probability of results at least as extreme as those observed.

What is alpha?

The significance threshold selected for deciding whether to reject the null hypothesis, often .05.

What does failing to reject the null mean?

The evidence is insufficient to reject it; this does not prove the null hypothesis true.

What does a statistically significant result mean?

The data meet the selected threshold for rejecting the null under the test’s assumptions.