Narrow or Broad? Estimating Subjective Specificity in Exploratory Search

Supporting exploratory search is a very challenging problem, not least because of the dynamic nature of the exercise: both the knowledge and interests of the user are subject to constant change. Moreover, whether the results for a query are informative is strongly subjective. What is informative to one user, is too specific for the other; specificity differs between users depending on their intent and accumulated knowledge about the domain.
We propose a formal model—motivated by Information Foraging Theory—for predicting the subjective specificity of search results based on simple observables such as result- clicks. Through two studies including both controlled and free-form exploratory search we show our model allows us to differentiate between levels of subjective result specificity with regard to the current information need of the user.