8. A computer-readable medium that comprises computer-executable instructions that when executed by a hardware processor cause the hardware processor to perform a method comprising: accessing data sources for data related to a user identified in content of a result, the data sources comprise self-generated data of the user and other-user generated data about the user; determining that profile information is missing for classification of the user on the social network; computing, based on the determining that the profile information is missing, candidate expertise summaries for the user based on the information sources and an inferred classification of the user generated from an evaluation of: popularity of the user including communications posted by the user, re-communications by other users of the communications posted by the user and mentions of the user by the other users in the social network; selecting an expertise summary from the candidate expertise summaries; and presenting the expertise summary for viewing in association with a user account of the user.
8. A computer-readable medium that comprises computer-executable instructions that when executed by a hardware processor cause the hardware processor to perform a method comprising: accessing data sources for data related to a user identified in content of a result, the data sources comprise self-generated data of the user and other-user generated data about the user; determining that profile information is missing for classification of the user on the social network; computing, based on the determining that the profile information is missing, candidate expertise summaries for the user based on the information sources and an inferred classification of the user generated from an evaluation of: popularity of the user including communications posted by the user, re-communications by other users of the communications posted by the user and mentions of the user by the other users in the social network; selecting an expertise summary from the candidate expertise summaries; and presenting the expertise summary for viewing in association with a user account of the user. 9. The computer-readable medium of claim 8 , wherein the method, executed by the hardware processor, further comprising selecting the expertise summary based on criteria applied to the candidate expertise summaries.