In the context of AP Psychology, what does statistical significance mean when interpreting research results?

• A. It suggests that the experiment was conducted without any bias or error.
• B. It shows that the sample size was large enough to guarantee accurate results.
• C. It means that the results are important and have practical value in real-world settings.
• D. It indicates that the observed results are unlikely to have occurred by chance alone and reflect a real effect.

Answer: (D)

Verified step by step guidance

1. Understand that statistical significance in psychology research refers to the likelihood that the observed results are not due to random chance.
2. Recognize that statistical significance is determined through hypothesis testing, where a null hypothesis (no effect) is tested against an alternative hypothesis (there is an effect).
3. Learn that a p-value is calculated, which represents the probability of obtaining the observed results if the null hypothesis were true.
4. Know that if the p-value is below a predetermined threshold (commonly 0.05), the results are considered statistically significant, meaning the null hypothesis is rejected.
5. Interpret statistical significance as an indication that the findings likely reflect a real effect in the population, but it does not necessarily imply practical importance or absence of bias.