In statistics, inconsistent data are values or observations that are distant from the other observations conducted on the same phenomenon, which means that it contrasts sharply with the values that are normally measured. An inconsistent result can be due to the inherent variability of the phenomenon observed or it can also indicate an experimental error. These inconsistent results are typically excluded from the data series when the results are analyzed.
Example
We surveyed 20 students at a primary school to find out their ages.
Here is the data we collected: 8, 9, 8, 9, 1, 9, 10, 10, 10, 8, 7, 8, 18, 7, 19, 7, 8, 8, 9, 10.
The data 1, 18 and 19 are inconsistent results.
They do not correspond to the normally-expected results.