What phenomenon refers to the tendency for extreme scores to move closer to the average over time?

The correct answer relates to the concept known as regression toward the mean. This phenomenon occurs when an extreme score, whether it is unusually high or low, is followed by subsequent measurements that are closer to the average. This happens due to the influence of various factors, including measurement error and natural variability.

When discussing this concept, it’s essential to recognize its implications in research and statistics. For instance, if an athlete performs exceptionally well in one season, it is likely that their performance in the following season will be closer to their average performance over time. This does not suggest that the individual has regressed in ability; instead, it highlights the natural fluctuations that occur within data sets.

Other choices represent distinct statistical concepts. A skewed distribution describes a situation where data points are not symmetrically distributed around a central value, which does not inherently imply that extreme values will revert to the average. A bimodal distribution indicates a distribution with two different modes, or peaks, which also does not pertain to the movement of extreme scores toward the average. Statistical significance is a measure used to determine whether the results observed in data are likely to be due to chance, but it does not address the tendency of scores to regress toward the mean.