<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (June 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (June 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> In statistics, the multiple comparisons, multiplicity or multiple testing problem occurs when one considers a set of statistical inferences simultaneously or infers a subset of parameters selected based on the observed values . In certain fields it is known as the look - elsewhere effect . </P> <P> The more inferences are made, the more likely erroneous inferences are to occur . Several statistical techniques have been developed to prevent this from happening, allowing significance levels for single and multiple comparisons to be directly compared . These techniques generally require a stricter significance threshold for individual comparisons, so as to compensate for the number of inferences being made . </P>

When do you need a multiple comparison test