C is the contingency coefficient.
d is Cohen’s d for the difference between two means.
df is degrees of freedom
f is Cohen’s measure for variance between means for more than two groups.
N is number of cases.
r is the point biserial correlation coefficient.
t is Student’s t.
η (eta) is the correlation ratio
Φ (phi) is the phi coefficient, sometimes written as rphi.
χ2 is chi-square.
The conversions between Φ and χ2 assume a 2 x 2 table.