The Impact of Accessibility and Usability on the Development of Web Applications G. Costagliola, F. Ferrucci, C. Gravino, G. Tortora, G. Vitiello Dipartimento di Matematica e Informatica, Università degli Studi di Salerno Via Ponte Don Melillo, 84084 Fisciano (SA), Italy {gcostagliola,fferrucci,gravino,tortora,gvitiello}@unisa.it Abstract. Ease of use is definitively one of the key aspects characterizing the quality of web applications and includes accessibility and usability. In this pa- per we describe how these factors can affect the development of web applica- tions. In particular, we describe the activities that should be targeted at accessi- bility based upon the W3C guidelines and propose a list of elements that could be used as predictors of the effort needed to ensure accessibility. As for the us- ability, we report on the tasks carried out to achieve this goal and the time commonly devoted to these tasks. 1. Introduction Several studies are currently being carried out to identify the factors that better define the quality of web applications [4,5,6]. Although some factors are not clearly under- stood, “ease of use” is definitively recognized to be one of the key aspects to distin- guish the quality of a web site. As a matter of fact, a European Commission’s bench- mark study carried out in November 2003 on quality and usage of public e-services in Europe reports that the most important factor for citizen satisfaction is ease of use of the web sites and for that reason many efforts are devoted to face the task of improv- ing web sites [9]. Several usability features contribute to determine ease of use, such as ease to find information/service, orientation and navigability, ease to learn. Many heuristics and guidelines are provided in the literature to design usable web sites [7]. Moreover, evaluation techniques have been widely experimented to measure user satisfaction [3,7]. Such techniques can be profitably exploited in a user-centered iterative devel- opment process. For users with disabilities the accessibility is a basic pre-requisite for the ease of use. Indeed, web accessibility is the ability to access to the web regardless of disabil- ity, thus it concerns with the possibility to read web pages, to navigate through the web sites, to interact with the procedures requiring choices and the input of data, to activate hypertext links, to download documents and so on. Since 1997 the World Wide Web Consortium (W3C) has started an initiative, called WAI (Web Accessibility Initiative), in order to guide web developers to the realization of accessible web pages for the greater number of people. In particular,