www.cmm.bristol.ac.uk/forum

I am still having this problem and would welcome any thoughts other forum members may have as to how I can solve it.

I have a large dataset of 80,000 records spread over 5 years and with records from both males/females and reception/year 6 pupils. I have successfully fitted a 2 level model with school and individual pupil as the two levels. This model seem to produce a reasonable fit although the variance ...