Dear all,

I'm running a fixed-effects model and need help interpreting sigma_u (between subject) and sigma_e (within subject) because an assessor requested me to fully explain their meaning. I have uploaded the output of model below. My dependent variable is school-mean test scores in maths. The independent variables include the years of the tests were performed: pb2009, pb2011, pb2013 and pb2015 compared to the base category pb2007.

Any help will be highly appreciated.

Thank you.

Luana.