Hi Eveline,

Thank you very much for the explanation. However, on the Conquest Version 2.0 manual that I have, the formula for calculating the Chi-square value X is the sum of (est^2/se) rather than (est/se)^2 (Wu, Adams, Wilson, & Haldane,2007, p160). I guess that is why it confuses me. So is (est^2/se) a typo?

Second question, could you explain more clearly why (est/se) is a standardized statistic? I understand that (x-mean x)/se = z score and z^2 is chi-square, but what is the proof that (est/se) itself is standardized?

Thanks!

Tong