Re: Weight of evidence (WOE)

Posted by David Marso on Jan 05, 2012; 2:09pm
URL: http://spssx-discussion.165.s1.nabble.com/Weight-of-evidence-WOE-tp5122524p5122737.html

Please provide the precise steps you use to calculate this in Excel.
A worked numerical example would be most informative.
If it can be done in Excel (painfully ) it can be done in SPSS with ease.
"W(v)=log(f(x=v|y=0)/f(y=v|y=1))."
does *NOT* provide sufficient information to work from.

DEBOER wrote

Hi,

I'm trying to validate a scorecard, first  I check on one variable at a time. My main question is if you can get "the weight of edevince (WOE)" in SPSS in an easy way? Or must one use excel all the time?

If too many values exist for a categorical variable then it is not feasible to enter them in the model as a series of indicator variables.
There will be too many of them and consequently coefficients will be poorly estimated.
A good solution is to substitute the categorical variable with the WOE for each value.

Recall:
is the WOE for value of variable .
WOE greater than 0 indicates a greater association with the negative event.
WOE less than 0 indicates a greater association with the positive event.

W(v)=log(f(x=v|y=0)/f(y=v|y=1)).

Then after getting WOE I want to calculate the information value.

I always use the formel above and get the results in excel but I hope that they is a easy way in SPSS.

Thanks in advance