I am trying to run an ANOVA with a within/between subjects design. It is a 2 (within) x 3 x 3 x 5 design with 100 observations per cell. When I am trying to run this, I get an error message saying that there is insufficient memory, even after allocating max memory for my machine (4 gig). We know the code works because we can do it with a smaller cell size. We can run a similar design that is only between-subjects with many more observations with no memory issue. Why does aov have trouble with within-subjects designs when the cell size gets large? Is there a way around this other than using another function like lme?