1. A computer-readable medium storing computer-executable instructions executed by a processor for causing a computer-controlled apparatus to implement a tag-mediated review system for electronic content, the executed computer-executable instructions performing a method comprising the steps of: obtaining on-line access to an infrastructure of a plurality of electronic source documents, wherein each electronic source document comprises source content supplied by an associated content producer and a plurality of content tags identifying subject matter contained within the source content; receiving a plurality of reviews concerning the accessed plurality of electronic source documents, each review expressing quality assessment information for a corresponding electronic source document by an associated reviewer and one or more review tags identifying subject matter addressed by the review; computing a tag-mediated content quality score for each electronic source document based at least in part on the plurality of received reviews, wherein the computed tag-mediated content quality score is based on tag scores for one or more of the corresponding content tags and one or more of the corresponding review tags; compiling a content quality information database storing the tag-mediated content quality scores in association with corresponding content tags, review tags and identifiers of the plurality of electronic source documents; receiving a document retrieval request; retrieving information identifying one or more electronic source documents responsive to the received document retrieval request and the tag-mediated content quality scores associated with the responsive one or more electronic source documents; and displaying information identifying the responsive electronic source documents and the associated tag-mediated content quality scores or ranking the responsive electronic source documents in a priority order based directly or indirectly on the associated tag-mediated content quality scores and displaying indicators for the responsive electronic documents in the priority order.