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’
    • ‘The above news reports mislead many readers into interpreting correlation as cause; post hoc as propter hoc; speculation as facts.’
    • ‘Thus, post hoc tests, such as linear contrasts, template correlations, and pairwise comparisons are used.’
    • ‘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.’
      • ‘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.’
      • ‘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.’


Latin, literally ‘after this’.


post hoc

/ˌpōst ˈhäk/