Papers by Giorgio Brajnik
While accessibility can be tested with respect to guidelines (like WCAG 1.0, or Section 508) thro... more While accessibility can be tested with respect to guidelines (like WCAG 1.0, or Section 508) through a standards review method, other methods can be employed, like user testing (DRC, 2004) or usability inspection methods (Preece et al., 2002; Gray and Salzman, 1998; Nielsen, 1993) or those suggested by Henry and Grossnickle (2004). To be really useful, evaluation methods should constrain the way in which the evaluator identifies problems and how they are graded in terms of importance.
The potential of Interactive Digital TV (IDTV) is enormous, given its reachability, the potential... more The potential of Interactive Digital TV (IDTV) is enormous, given its reachability, the potential ability to provide highly personalized services (when users identify themselves using smartcards, for example to get access to individual egovernment services, to health information and services, to social networks), and to act as yet another outlet for using the web.
Abstract This paper presents a Monte Carlo method for analyzing the space of trajectories entaile... more Abstract This paper presents a Monte Carlo method for analyzing the space of trajectories entailed by a qualitative di erential equation and deriving statistical properties of qualitative behaviors. Estimates of the occurrence probability of behaviors and estimates of parameters de ned over numerical trajectories can be computed and used in several ways. For example, behavior probability can be used to rank behaviors and discard those below a signi cance threshold.
Abstract Web site evaluation methodologies and validation engines take the view that all accessib... more Abstract Web site evaluation methodologies and validation engines take the view that all accessibility guidelines must be met to gain compliance. Problems exist in this regard as contradictions within the rule set may arise, and the type of impairment or its severity is not isolated. The Barrier Walkthrough (BW) method goes someway to addressing these issues by enabling barrier types derived from guidelines to be applied to different user categories such as motor or hearing impairment, etc.
Viene discussa l'importanza e il ruolo di interfacce intelligenti a sistemi di information retrie... more Viene discussa l'importanza e il ruolo di interfacce intelligenti a sistemi di information retrieval nel reperimento di informazioni che effettivamente soddisfino i bisogni informativi degli utenti. La linea di ricerca FIRE ha avuto come obiettivo sviluppo e sperimentazione di un'interfaccia intelligente (basata su rappresentazione esplicita della conoscenza) ad un sistema di information retrieval di tipo booleano.
Abstract Incomplete information is present in many engineering domains, hindering traditional and... more Abstract Incomplete information is present in many engineering domains, hindering traditional and non {traditional simulation techniques. This paper describes SQPC (semi {quantitative physics compiler), an implemented approach to modelling and simulation that can predict the behavior of incompletely speci ed systems, such as those that arise in the water control domain. SQPC is the rst system that uni es compositional modeling techniques with semi {quantitative representations.
Qualitative simulation methods Kuipers, 1994] are based on a formalism (Qualitative Di erential E... more Qualitative simulation methods Kuipers, 1994] are based on a formalism (Qualitative Di erential Equations, QDE) that describes a whole family of ordinary di erential equations. Such a formalism can be used to specify a family of initial value problems that can be solved qualitatively by the Qsim algorithm. The qualitative solution consists of a ( nite) set of qualitative descriptions of trajectories (called behaviors). Qsim does not provide any probabilistic characterization of the behaviors, and this would be very bene cial for all of Qsim's applications.
Abstract The paper starts with an overview of major problems hindering effective interactions wit... more Abstract The paper starts with an overview of major problems hindering effective interactions with information retrieval systems. A brief review of models of the interaction taking place during information seeking is then provided with the aim of lying the ground for yet another model based on two levels of interaction: presentation and navigation. The former encompasses interactions with the user interface of the retrieval system, whereas the latter deals with the interaction that users experience with the information resource.
Abstract The talk will highlight several issues related to processes that are normally used to as... more Abstract The talk will highlight several issues related to processes that are normally used to assess, and sometimes, measure the accessibility level of web sites. These processes include sampling pages, testing and analyzing them, and measuring their accessibility level. In many cases these processes introduce bias and errors, leading to wrong and invalid conclusions about accessibility.
Abstract. Testing accessibility of a web site is still an art. Lack of appropriate definitions of... more Abstract. Testing accessibility of a web site is still an art. Lack of appropriate definitions of accessibility and of standard testing methods are some of the reasons why Web accessibility is so difficult to achieve. The paper describes a heuristic walkthrough method based on barriers; it then discusses how methods like this can be evaluated, and it shows experimental data about validity and usefulness of the method when compared to standards review.
ABSTRACT This paper raises the need for quantitative accessibility measurement and proposes three... more ABSTRACT This paper raises the need for quantitative accessibility measurement and proposes three different application scenarios where quantitative accessibility metrics are useful: Quality Assurance within Web Engineering, Information Retrieval and accessibility monitoring. We propose a quantitative metric which is automatically calculated from reports of automatic evaluation tools.
Le tecnologie per il reperimento delle informazioni stanno assumendo un ruolo sempre pi u importa... more Le tecnologie per il reperimento delle informazioni stanno assumendo un ruolo sempre pi u importante in applicazioni che vanno dall'accesso a banche dati bibliografiche alla navigazione in una rete di risorse informative.
Abstract. Testing accessibility of a web site is still an art. The paper examines the currently k... more Abstract. Testing accessibility of a web site is still an art. The paper examines the currently known definitions of accessibility and claims that lack of appropriate standardization of definitions and testing methods is one of the reasons explaining why web accessibility is so difficult to achieve. The paper suggests that a method based on heuristic walkthrough might help evaluators in better assessing accessibility.
Abstract Web sites of official organizations should be accessible to reduce the digital divide an... more Abstract Web sites of official organizations should be accessible to reduce the digital divide and improve the ability of any citizen to participate to the social and political life of a country. However the current status of web sites is far from satisfying. Despite the existence of standards and regulations, many organizations still host web sites that are not accessible.
Abstract Text transcoders are web--server systems that produce, on the fly, a text-only version o... more Abstract Text transcoders are web--server systems that produce, on the fly, a text-only version of a web page requested by a user of a browser. Although the potential benefits of text transcoders axe multifaceted and discussions on appropriateness of text transcoders to produce accessible versions of web sites are still ongoing, at the moment the impact of transcoded pages on disabled web users has not been scientifically studied yet.
Abstract Although no unified definition of the concept of search strategy in Information Retrieva... more Abstract Although no unified definition of the concept of search strategy in Information Retrieval (IR) exists so far, its importance is manifest: nonexpert users, directly interacting with an IR system, apply a limited portfolio of simple actions; they do not know how to react in critical situations; and they often do not even realize that their difficulties are due to strategic problems.
Abstract Access is what the web is' about', it is the motivation behind its creation, and it is t... more Abstract Access is what the web is' about', it is the motivation behind its creation, and it is the rationale behind HTML. The desire to provide all users at CERN with the ability to access all documents was Tim Berners-Lee's primary goal, and this goal must also be carried through to equal access for all users. But this equality of access--accessibility--is difficult to quantify, define, or agree upon.
Abstract. Although the potential benefits of text transcoders are multifaceted, at the moment the... more Abstract. Although the potential benefits of text transcoders are multifaceted, at the moment their impact on disabled web users is not clear. This paper describes an experiment aimed at evaluating usability of web pages processed by a text transcoder and used by disabled persons. Results based on subjective and objective data show how usability changes.
In this paper we argue that while there exist several approaches to modeling user interfaces of w... more In this paper we argue that while there exist several approaches to modeling user interfaces of web applications when adopting a Model Driven Development methodology, too little attention is payed to the actual abstract behavior of the interface. In the UML-IDEA approach we adopt the UML as a modeling language and start from a very abstract view of the UI specified in terms of state machines. We claim that expressivity of the language is sufficient to capture, even at the abstract level, many usability problems. At the same time, transformations of models into more concrete levels generate executable code and test cases, wireframe prototypes and representations suitable also for accessibility assessments. In this way usability and accessibility investigations could be carried out during conceptual design.
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Papers by Giorgio Brajnik