Question

Hello,

How do I interpret Nagelkerke R Square and Exp (B)? Gender (1) reference is Male

Model Summary
Step	-2 Log likelihood	Cox & Snell R Square	Nagelkerke R Square
1	333.315a	.006	.009

a. Estimation terminated at iteration number 4 because parameter estimates changed by less than .001.

Classification Tablea
	Observed		Predicted
			Undergrad Degree		Percentage Correct
			Natural Science	Social Science
Step 1	Undergrad Degree	Natural Science	268	0	100.0
		Social Science	67	0	.0
	Overall Percentage				80.0

a. The cut value is .500

Variables in the Equation
		B	S.E.	Wald	df	Sig.	Exp(B)
Step 1a	Gender (1)	.036	.291	.015	1	.902	1.036
	Student Age	-.021	.015	1.908	1	.167	.979
	Constant	-.699	.567	1.523	1	.217	.497

a. Variable(s) entered on step 1: Gender , Student Age.

Answer 1

• Cox and Snell's R ² is based on the log likelihood for the model compared to the log likelihood for a baseline model. However, with categorical outcomes, it has a theoretical maximum value of less than 1, even for a "perfect" model.
• Nagelkerke's R ² is an adjusted version of the Cox & Snell R-square that adjusts the scale of the statistic to cover the full range from 0 to 1.

Exp(B) is odds-ratio

a one-unit change in the variable corresponding to B will multiply the relative risk of the outcome (compared to the base outcome) by 1.036