Final answer:
Events outside the normal behavior of datasets are known as outliers, which can significantly affect statistical calculations and may indicate errors or new phenomena.
Step-by-step explanation:
Events outside the normal behavior of datasets are called outliers. An outlier is an observation that lies an abnormal distance from other values in a random sample from a population. In a set of data, outliers can drastically affect the mean and standard deviation, leading to significant statistical biases. These outliers might be due to variability in the measurement or could indicate experimental error; the latter sometimes provides insight into a new phenomenon or mistake and should be investigated.
For example, the value 740 in a dataset of exam scores from 0 to 100 is an outlier that might be a data entry error, and should be reviewed for accuracy.