P-hacking

P-hacking is a colloquial term for the process of manipulating – perhaps unconsciously - the process of statistical analysis and the degrees of freedom until they return a figure below the p<.05 level of statistical significance. This is achieved by dropping one of the experimental conditions in the results so that the overall p-value would be less than .05.

This can be avoided by ensuring where appropriate, that the design of an experiment includes a clear statement proposing the analyses to be undertaken.