Aspects of form in the design of Web sites: Surface affordances and hidden depths

Aspects of form in web sites, in particular, visual, navigational, and verbal complexity, are investigated in a random effects study using a set of uniquely generated web sites in which a number of determinants of formal complexity were manipulated. These included manipulations of the graph-theoretic structure of the site, the number and density of hyperlinks, the amount of screen real estate allocated to textual, visual, and navigational elements, and levels of reading difficulty. Software for generating a large number of unique web sites for the experiment was developed and is discussed. A total of 528 subjects recruited from a panel of science fiction fans were asked to assess their experience of the experimental web sites (the content materials for which concerned the SETI project) using measures of perceived ease of use, perceived usefulness, attitude toward the site, future intention, recall, and satisfaction. Despite the application of a number of known complexity manipulations, it was found that these measures of formal aspects of design confer little predictive power in determining user acceptance. Future prospects for the evaluation of aspects of form for media such as web sites are discussed.