Type: descriptive statistic only
Measurement level: Correlate: dichotomous, Happiness: metric
Range: [-1; +1]
Meaning: The point bi-serial coefficient of correlation is the Pearson's coefficient correlation which is obtained if the correlate is an "indicator variable", i.e. a variable which only adopts the values 0 and 1.
rpb = 0 « no correlation established
rpb = 1 « at correlate level 1 only higher happiness ratings and at correlate level 0 only lower happiness ratings
rpb = -1 « at correlate level 1 only lower happiness ratings and at correlate level 0 only higher happiness ratings.