Allowing [statistical software] to do our 
        thinking is a sure recipe for disaster. 
                                               (Good & Hardin, 2012, p. xi)
    - or did it really?
    «Simple» statistical tests
    •                  2
       chi-square (X  ) test
    •  t-test
    - or did it really?
    Statistical hypothesis testing
    1. Formulate a hypothesis
           E.g. In Norwegian L2, Vietnamese have more TENSE errors than 
            Somali.
    2. Formulate a null-hypothesis
           Vietnamese and Somalis have the same rate of TENSE errors.
    3. «Disprove» the null-hypothesis = demonstrate its 
        unlikelihood
           E.g. less than 5% chance for the null-hypothesis to be true
           = «Significance»
    •  We choose α according to what we consider an acceptable 
       risk of false conclusions
         Often 5% in linguistic research
    - or did it really?
    Conditions of use
    •  Independent observations
         chi-square test
         t-test
    •  Parametric assumptions
         t-test
    •  The dangers of repeated testing
         any test
    - or did it really?
   A simple example from ornithology
   - or did it really?