In
single blind reviews, the identities of the reviewers are kept hidden from the authors, to protect reviewers from retribution and/or undue influence.
In
double-blind reviews, the identities of authors and reviewers are kept hidden from each other, with the added benefit of insulating the reviewers from bias for or against the author(s).
The literature deems double-blind reviewed articles as being of higher quality than single-blind or unblinded reviews. Men and (strangely) women display a vias topwards women authors and of course nepotism is always a factor.
A great article on this is
found here.
