Date:         Sun, 30 Jan 2000 20:37:30 +0800
Reply-To:     Lianjiang Li <lianli@NET1.HKBU.EDU.HK>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Lianjiang Li <lianli@NET1.HKBU.EDU.HK>
Subject:      Fw: logistic regression and levels of measurement
Content-Type: text/plain; charset="iso-8859-1"

When I entered Age as a continuous variable into a multivariate logisitic
regression model (response was dichotomous), the result showed it had very
small beta and was insignificant (p = .35).  But when I recoded Age into a
five-point ordinal variable and included it in the same model, it had a much
larger beta and was highly significant (p = .002).  I assume that the change
of betas was due to the change of unit of change of the predictor, but I'd
like to be reassured that the significance level change was due to the same
thing.

 More puzzling is that when I did the same thing with ordinal logit analysis
 with GOLDMineR, I observed similar change of betas, but the significance
 levels of the predictor Age remained largely unchanged regardless of its
 levels of measurement.

 Any advice would be greatly appreciated.

Lianjiang Li
Hong Kong Baptist University