The final question is whether the paper is significant and relevant, i.e., whether it has anything of importance to say and whether it is appropriate for the journal in which it is to be printed. Usually the referee's task would be hopelessly formidable unless the referee isn't already familiar with the field. This is idea behind peer review - the referees should be people who are already familiar with the literature in the field, the experimental techniques used. Peer review is ordinarily done blind - this means that the author is not told who the reviewers are. Some are done double blind - in double blind reviewing the reviewers don't know who the author is either.
Double blind is better because it removes an element of bias.
Note however that in many fields everybody is familiar with everybody else's work and they don't have any trouble figuring out who the reviewers and the authors are. The process of getting a paper published cycles through several stages of review. First the reviewers read the paper and make their comments. These are fed back to the author who revises his paper to make suggested corrections and improvements and to answer criticisms that he or she feels are incorrect. All of this should sound very good - all very painstaking with all of the possible sources of error made as small as possible.