HARKing

HARKing (hypothesizing after the results are known) is an acronym coined by social psychologist Norbert Kerr that refers to the questionable research practice of "presenting a post hoc hypothesis in the introduction of a research report as if it were an a priori hypothesis". Hence, a key characteristic of HARKing is that post hoc hypothesizing is falsely portrayed as a priori hypothesizing. HARKing may occur when a researcher tests an a priori hypothesis but then omits that hypothesis from their research report after they find out the results of their test. Post hoc analysis or post hoc theorizing then may lead to a post hoc hypothesis.

== Types == Several types of HARKing have been distinguished, including: THARKing: Transparently hypothesizing after the results are known, rather than the secretive, undisclosed, HARKing that was first proposed by Kerr. In this case, researchers openly declare that they developed their hypotheses after they observed their research results. CHARKing (or Pure HARKing): CHARKing or "pure HARKing" refers to the practice of constructing new hypotheses after the results are known and presenting them as a priori hypotheses. CHARKing is often regarded as the prototypical form of HARKing. RHARKing: RHARKing refers to retrieving old hypotheses from the existing literature after the results are known and presenting them as a priori hypotheses Note that RHARKed hypotheses can be considered to be a priori hypotheses in the sense that they were developed and published prior to knowledge of the current research results. SHARKing: Suppressing a priori hypotheses after the results of tests of those hypotheses are known. Active and passive HARKing: Active HARKing occurs when researchers HARK prior to submitting their research report for publication. Passive HARKing occurs when researchers HARK in response to requests by editors and reviewers during the peer review process.