1. A computer-implemented method comprising: receiving machine-readable member profile information characterizing a first member and a second member in a member network; receiving a first search query submitted by the first member and a second search query submitted by the second member; responding to each of the first search query and the second search query with a) links to a collection of articles and b) one or more links for receiving input characterizing respectively ratings of the first member and ratings of the second member of articles in the collection; receiving a selection by the first member of a link for receiving input characterizing the first member's rating of a first of the articles in the collection; receiving a selection by the second member of a second link for receiving input characterizing the second member's rating of the first of the articles; storing machine-readable information characterizing the first member's rating and machine-readable information characterizing the second member's rating; receiving a third search query submitted by a third member, wherein the third search query is identical or relevant to the first search query and the second search query and the third member is not explicitly associated with the first member in the member network; determining a collection of articles that are responsive to the third search query, wherein the collection includes the first of the articles; identifying that the member profile information of the first member in the member network is associated with the third search query by virtue of the member profile information describing that the first member has expertise in a field associated with the third search query; and providing the third member with information describing the collection of articles responsive to the third search query and information describing an availability of the information characterizing the first member's rating of the first of the articles, wherein the information provided to the third member excludes any indication that information characterizing the second member's rating of the first of the articles has been received.