The role of the observer in the Everett interpretation
  The role attributed to the observer in various interpretations of quantum mechanics as well as in classical statistical mechanics is discussed, with particular attention being paid to the Everett interpretation. In this context, the important difference between "quasi-classical" (robust against decoherence) and "macroscopically given" (rather than being part of a thermodynamic ensemble) is pointed out. 
H. Dieter Zeh
quant-ph gr-qc physics.hist-ph