Model-directed web transactions under constrained modalities

Online transactions (e.g., buying a book on the Web) typically involve a number of steps spanning several pages. Conducting such transactions under constrained interaction modalities as exemplified by small screen handhelds or interactive speech interfaces - the primary mode of communication for visually impaired individuals - is a strenuous, fatigue-inducing activity. But usually one needs to browse only a small fragment of a Web page to perform a transactional step such as a form fillout, selecting an item from a search results list, etc. We exploit this observation to develop an automata-based process model that delivers only the "relevant" page fragments at each transactional step, thereby reducing information overload on such narrow interaction bandwidths. We realize this model by coupling techniques from content analysis of Web documents, automata learning and statistical classification. The process model and associated techniques have been incorporated into Guide-O, a prototype system that facilitates online transactions using speech/keyboard interface (Guide-O-Speech), or with limited-display size handhelds (Guide-O-Mobile). Performance of Guide-O and its user experience are reported.