Patent ID: 8868565

Claim:
A method performed by a data processing apparatus, comprising: identifying user click durations for resources corresponding to a first resource quality measure and identifying user click durations for resources corresponding to a second resource quality measure that is different from the first quality measure, each of the user click durations for a resource being a measure of elapsed time that the first resource is displayed at a user device following a selection of the resource; for each of a plurality of resource categories: determining based on the user click duration from click durations for first resources that are each categorized as belonging to the resource category and that have a quality measure that is within a threshold range of the first resource quality measure, a short click duration specifying a first threshold click duration that is used to classify a user click duration as a short click; and determining, based on the user click duration from click durations for second resources that are each categorized as belonging to the resource category and that have a quality measure that is within a threshold range of the second resource quality measure, a long click duration specifying a second threshold click duration that is used to classify a user click duration as a long click; wherein the determined short click durations are different for at least two of the categories, and the determined long click durations are different for at least two of the categories; and classifying a user click duration corresponding to a selection of a resource from one of the categories based, at least in part, on the short click duration and the long click duration for the one of the categories.