Hi all, I am estimating a lmer model and now I would like to test whether some coefficients for specific levels of factor variable are equal. I am thinking of either: (1) applying equality constraints on several parameters for specific levels of a factor variable (and use that to do LRT against model without equality constraints), but I have no clue on how to that; or (2) do a Wald test in which several parameter estimates of a factor variable are jointly tested. Although I noticed "wald.test" from the "aod" package, but I don't quite follow how to apply that to my lmer model. Any suggestions on how to jointly test several parameters of a lmer model (preferably applied to factor variables)? Stijn
Best regards, Stijn Ruiter Department of Sociology / ICS Radboud University Nijmegen P.O. Box 9104 6500 HE Nijmegen Netherlands Phone: + 31 24 361 2272 Fax: + 31 24 361 2399 Visiting address: Thomas van Aquinostraat 4.01.71 Nijmegen website: http://oase.uci.ru.nl/~sruiter