Accession Number : ADA462156


Title :   SNIF-ACT: A Cognitive Model of User Navigation on the World Wide Web


Corporate Author : ILLINOIS UNIV AT URBANA-CHAMPAIGN SAVOY AVIATION HUMAN FACTORS DIVISION


Personal Author(s) : Fu, Wai-Tat ; Pirolli, Peter


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a462156.pdf


Report Date : 03 Jan 2007


Pagination or Media Count : 68


Abstract : We describe the development of a computational cognitive model that explains navigation behavior on the World Wide Web (WWW). The model, called SNIF-ACT (Scent-based Navigation and Information Foraging in the ACT cognitive architecture), is motivated by Information Foraging Theory (IFT), which quantifies the perceived relevance of a Web link to a user goal by a spreading activation mechanism. The model assumes that users evaluate links on a Web page sequentially, and decide to click on a link or to go back to the previous page by a Bayesian satisficing model (BSM) that adaptively evaluates and selects actions based on a combination of previous and current assessments of the relevance of link texts to information goals. The model was tested against data collected from novice users engaged in unfamiliar information-seeking tasks. SNIF-ACT 1.0 utilizes the measure of utility, called information scent, derived from IFT to predict rankings of links on different Web pages. The model was tested against a detailed set of protocol data collected from eight subjects as they engaged in two information-seeking tasks using the WWW. The model provided a good match to subjects link selections and decisions to leave a Web site, and thus provided support for the use of information scent as a psychological measure of the perceived relevance of link text to information goals. In SNIF-ACT 2.0, we include an adaptive link selection mechanism that sequentially evaluates links on a Web page according to their position. The mechanism was derived based on a rational analysis of link selection on a Web page. The mechanism allowed the model to dynamically update the evaluation of actions (e.g., to follow a link or leave a Web site) based on sequential assessments of link texts on a Web page, and to decide when to leave a page based on experiences with previous pages. SNIF-ACT 2.0 was validated on a data set obtained from 74 subjects. Monte Carlo simulations of the model showed that SNIF-ACT 2


Descriptors :   *MATHEMATICAL MODELS , *NAVIGATION , *INTERNET , COGNITION , INTERNET BROWSERS , USER NEEDS , BEHAVIOR


Subject Categories : Information Science
      Psychology
      Computer Programming and Software
      Human Factors Engineering & Man Machine System


Distribution Statement : APPROVED FOR PUBLIC RELEASE