This will often happen if you fit a regression model with one strong
binary predictor and one or more continuous predictors. You don't say
what sort of analysis you did.
Doug
At 22:52 12/09/2006, Brian Mcmillan wrote:
>Hello all,
>
>Does anyone know what might cause a gap in the middle of a residuals plot?
>(predicted values plotted against residuals)
>
>I'm guessing it could be one of two things - a range of outcome values
>that never occur, or a range of predictor varibles that never occur,
>possibly caused by combining two data sets measuring variables that have
>very different ranges?
>
>Hmmm.....
>
>Any thoughts welcome! Thanks in advance,
>Brian
_____________________________________________________
Doug Altman
Professor of Statistics in Medicine
Centre for Statistics in Medicine
Wolfson College Annexe
Linton Road
Oxford OX2 6UD
email: [log in to unmask]
Tel: 01865 284400 (direct line 01865 284401)
Fax: 01865 284424
Web: http://www.csm-oxford.org.uk/
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