Try a look at this: http://stat.ethz.ch/R-manual/R-patched/library/MASS/html/stepAIC.html Regards, Phil -- View this message in context: http://r.789695.n4.nabble.com/All-combinations-possible-in-a-mutliple-regression-tp4639762p4639782.html Sent from the R help mailing list archive at Nabble.com.