Definition of post hoc in US English:

post hoc


  • Occurring or done after the event, especially with reference to the fallacious assumption that the occurrence in question has a logical relationship with the event it follows.

    ‘a post hoc justification for the changes’
    • ‘Thus, post hoc tests, such as linear contrasts, template correlations, and pairwise comparisons are used.’
    • ‘The above news reports mislead many readers into interpreting correlation as cause; post hoc as propter hoc; speculation as facts.’
    • ‘The results of my study were negative, and the journal reviewer insists that I perform a post hoc power calculation.’


  • After the event.


  • post hoc, ergo propter hoc

    • After this, therefore resulting from it: used to indicate that a causal relationship has erroneously been assumed from a merely sequential one.

      • ‘The relevant fallacy is post hoc ergo propter hoc.’
      • ‘When I say that post hoc ergo propter hoc is my favorite fallacy, I mean two things: first, I am a nerd, and second, I love that this simple phrase diagnoses so many logical and scientific missteps.’
      • ‘The fallacy of Post Hoc Ergo Propter Hoc occurs when something is assumed to be the cause of an event merely because it happened before that event.’


Latin, literally ‘after this’.


post hoc

/ˌpōst ˈhäk/