Question 16

If the results of a study are statistically significant, they are most likely not due to chance.

Statistical significance indicates that the observed effects in a study are unlikely to have occurred randomly, suggesting a genuine relationship between variables. In the context of the professor's study, this means that any differences in exam scores due to varying noise levels are likely attributable to the noise itself rather than random variation.

A) most likely cannot be replicated

This option is incorrect because statistical significance does not imply that results cannot be replicated. In fact, statistically significant results are often expected to be replicable under similar conditions if the study is sound.

B) have practical significance

While statistically significant results can sometimes have practical significance, this is not guaranteed. Practical significance refers to the real-world relevance or impact of the findings, which is separate from the statistical determination of significance.

C) are the opposite of what was predicted

This option is incorrect as statistical significance does not imply that results contradict predictions. It simply means that the findings are unlikely to be due to chance, regardless of whether they support or oppose the initial hypothesis.

D) are most likely not due to chance

This option is correct because statistical significance indicates that the results observed in the study are unlikely to have occurred by random chance alone. This means that the differences in exam scores observed in the study likely stem from the manipulation of noise levels.

Conclusion

In summary, option D is definitively correct as it aligns perfectly with the definition of statistical significance, indicating that results are likely due to the experimental conditions rather than random variation. All other options either misinterpret the concept of statistical significance or present incorrect assertions regarding the replicability and implications of study results.