We are using double-blind reviewing again this year. Authors were asked to take reasonable efforts to hide their identities, including not listing their names or affiliations and omitting acknowledgements. This information will, of course, be included in the published version, should the paper be accepted.
One area where anonymity can affect your evaluation of the submitted paper is if the paper builds on ideas that were previously available in some prepublications form, for instance as a SIGGRAPH Talk, or as a technical report or thesis. The authors were instructed to avoid plagiarism, and to cite their sources if they used ideas from somebody else’s work. They should have also cited all their own prepublications in an anonymous way (see Submission Policy). Reviewers should not deliberately try to follow such citations back to the authors; these citations are only mentioned as a means to ascertain that content you have independently discovered (online or otherwise) as part of your reviewing due diligence was written by the same authors — and thus does not constitute plagiarism.
Due to the number of new works posted on arXiv and other non-peer-reviewed websites on a daily basis, it is increasingly likely that you might find online reports that are highly relevant to the submitted work, and that the authors were unaware of. In this case, authors of conditionally accepted papers should be asked to cite these prepublications in their final revision. Note that authors are allowed to cite them as concurrent work, without the burden of having to detail how their work compares or differs from these prepublications.