Describe a situation with two variables and an outlying score that would warrant further investigation into the cause of its outlying value. Solution Outliers from data errors. Outliers are often caused by human error, such as errors in data collection, recording, or entry. Data from an interview can be recorded incorrectly, or miskeyed upon data entry. One survey the first author was involved with (reported in Brewer, Nauenberg, & Osborne, 1998) gathered data on nurses.