1. A computer-implemented method, comprising: receiving a request; inferring a request reading level representation for the request, inferring the request reading level representation for the request being based at least in part on previous behavior prior to the request, the previous behavior comprising a set of behavior, the set of behavior being computer-based search behavior or computer-based browsing behavior, the inferring the request reading level representation comprising: defining a search session that includes the request; identifying one or more search actions prior to the request in the search session; and inferring a reading level from the one or more search actions prior to the request in the search session; in response to the request, comparing the request reading level representation with one or more reading difficulty level representations for one or more response items; and in response to the request, returning one or more indications of results of comparing the request reading level representation with one or more reading difficulty level representations for the one or more response items.
1. A computer-implemented method, comprising: receiving a request; inferring a request reading level representation for the request, inferring the request reading level representation for the request being based at least in part on previous behavior prior to the request, the previous behavior comprising a set of behavior, the set of behavior being computer-based search behavior or computer-based browsing behavior, the inferring the request reading level representation comprising: defining a search session that includes the request; identifying one or more search actions prior to the request in the search session; and inferring a reading level from the one or more search actions prior to the request in the search session; in response to the request, comparing the request reading level representation with one or more reading difficulty level representations for one or more response items; and in response to the request, returning one or more indications of results of comparing the request reading level representation with one or more reading difficulty level representations for the one or more response items. 10. The method of claim 1 , wherein the request reading level representation comprises a reading level distribution over multiple distribution reading levels with the reading level distribution over multiple distribution reading levels comprising, for each of the multiple distribution reading levels, an indication of a probability that an item at that distribution reading level will be understood.