Dear R users: I've a problem with lme function, when I want to model an unbalanced two-way anova, with 2 random factors say t and b. My two models are: model1- y(ijk) = beta+b(i)+t(j)+epsilon(ijk) model2- y(ijk)= beta+b(i)+t(j)+b:t(ij)+epsilon(ijk) beta overall mean effect The data.frame is X t b med celda 1 1 10 1 1 1 12 1 1 1 11 1 1 2 13 2 1 2 15 2 1 3 21 3 1 3 19 3 2 1 16 4 2 1 18 4 2 2 13 5 2 2 19 5 2 2 14 5 2 3 11 6 2 3 13 6 I try with lme to obtain the variance estimates like with varcomp, for model1 model-2, sum and interaction effects. varcomp gives me: variance estimates: t 0 b 0 t:b 7.407 residuals 3.8429 I try with lme: x <- lme(med~ 1, data = X;random = ~ 1 | t+b or random = ~t+b | celda random = ~t*b | celda random = ~ 1 | t*b , method = "ML") I get "bad groupping" or "singular convergence". Please, Can anyone tell me how to model, model-1 and model-2 in lme. Do you know any library for S-PLUS, R in order to get like in SPSS expected mean squares if no library, how obtain in S-PLUS, R? My e-mail is darkjacknife at hotmail.com _________________________________________________________________ Protege tu correo del spam y los virus con MSN 8. Prueba gratis dos meses MSN 8. http://join.msn.com/?pgmarket=es-es&XAPID=199&DI=1055