7. A computer-implemented method comprising: identifying a reference resource and a contextual profile for the reference resource; determining that relevance feedback data for the reference resource has at least a threshold level of similarity to the contextual profile for the reference resource, the determination being based on a difference between the relevance feedback data and topics specified by the contextual profile, the relevance feedback data specifying one or more topics that users have identified as relevant to the reference resource; in response to the determination, computing, by a data processing device, a first contextual profile for a different resource based on the contextual profile for the reference resource; normalizing topic values of the first contextual profile to normalized topic values for the first contextual profile, the normalized topic values being values on a normalized scale; adjusting, to a baseline value, each of the normalized topic values that is less than a first topic value threshold; re-normalizing the normalized topic values having values that are different than the baseline value subsequent to the adjusting; and re-computing the first contextual profile based on a function of the re-normalized topic values and the contextual profile for the reference resource.
7. A computer-implemented method comprising: identifying a reference resource and a contextual profile for the reference resource; determining that relevance feedback data for the reference resource has at least a threshold level of similarity to the contextual profile for the reference resource, the determination being based on a difference between the relevance feedback data and topics specified by the contextual profile, the relevance feedback data specifying one or more topics that users have identified as relevant to the reference resource; in response to the determination, computing, by a data processing device, a first contextual profile for a different resource based on the contextual profile for the reference resource; normalizing topic values of the first contextual profile to normalized topic values for the first contextual profile, the normalized topic values being values on a normalized scale; adjusting, to a baseline value, each of the normalized topic values that is less than a first topic value threshold; re-normalizing the normalized topic values having values that are different than the baseline value subsequent to the adjusting; and re-computing the first contextual profile based on a function of the re-normalized topic values and the contextual profile for the reference resource. 8. The method of claim 7 , wherein re-computing the first contextual profile comprises summing the contextual profile for the reference resource and the re-normalized topic values.