Information extraction from the Web is of growing importance. Objects on the Web are often associated with many attributes that describe the objects. It is essential to extract these attributes and map them to their corresponding objects. However, much attribute information about an object is hidden in the dynamic user interaction and is not on the Web page that describes the object. Existing information extraction approaches focus on getting information from the object Web page only, which means a lot of attribute information is lost. In this paper, we study the dynamic user interaction on exploratory search Websites and propose a novel link-based approach to discover attributes and map them to objects. We build an exploratory search model for exploratory Web sites, and we propose algorithms for identifying, clustering, and relationship mining of related Web pages based on the model. Using the unsupervised method in our approach, we are able to discover hidden attributes not explicitly shown on object Web pages. We test our approach on two online shopping Websites. We achieve high precision and recall: For entirely crawled Web sites the precision and recall are 98% and 97% respectively. For randomly crawled (sampled) Web sites the precision and recall are 98% and 80% respectively.