you know  er it helps if erm it helps if the groups that you're comparing between there's about sort of at least twenty people in each sort of thing, erm  and the same goes for things like, things that you might want to do  squares on or something like that erm so i mean if you were interested in comparing people who attended very regularly with people who only attended once in a while erm you know it would help if there were about sort of  more than forty people altogether so that there was sort of, you know