AP Psychology Practice Test

What does statistical significance indicate?

1. The importance of the mean score

2. Rejection of the assumption of no differences

3. The reliability of the data collection method

4. The size of the data sample used in a study

The correct answer is: Rejection of the assumption of no differences

Statistical significance indicates that the observed effects or differences in a study are unlikely to have occurred by chance alone, leading researchers to reject the null hypothesis, which assumes no differences or effects. By establishing statistical significance, researchers can infer that there is likely a true effect present, rather than attributing findings to random variability. The importance of the mean score, the reliability of the data collection method, and the size of the data sample used in a study, while relevant factors in research, do not specifically define what statistical significance means. Statistical significance is fundamentally concerned with determining whether the evidence suggests the presence of a genuine effect or difference rather than randomness, which is why the concept of rejecting the assumption of no differences is the most accurate representation of what statistical significance indicates.