[R] Block factor as random or fixed effect?

[Rob Knell]

People

I apologise for asking a general stats question, but I'm at a bit of a  
loss as to what to do following some hostile referees' comments. If I  
have a fully randomised blocked design, with only three blocks, should  
I treat block as a random or fixed effect? I have read comments about  
not treating block as a random effect if the number of blocks is less  
than 6 or 7: is this right?

Any advice much appreciated

Rob Knell


School of Biological and Chemical Sciences
Queen Mary, University of London

'Phone +44 (0)20 7882 7720
Skype Rob Knell

Research: http://webspace.qmul.ac.uk/rknell/