Orientador: Heloísa Vieira da Rocha / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-20T14:48:06Z (GMT). No. of bitstreams: 1 Vargas_Ariel_D.pdf: 20092407 bytes, checksum: a759e10b287a819834ba069524f29fee (MD5) Previous issue date: 2012 / Resumo: Observar as ações de usuários interagindo com a interface de uma aplicação computacional é a base de métodos tradicionais de avaliação de usabilidade, como os testes com usuários e a observação em campo. Apesar de populares e eficientes na descoberta de problemas, esses métodos tradicionais são considerados bastante caros, devido aos custos de envolver usuários, de preparar a infra-estrutura e especialmente da própria execução dos métodos e análise de seus resultados. A qualidade dos resultados da execução desses métodos depende da escolha dos usuários participantes da avaliação, que precisam ser representativos de todos os perfis de usuários da aplicação avaliada. Na Web, devido à diversidade e característica distribuída dos usuários, a obtenção de usuários representativos dos diversos perfis torna-se bastante difícil. Nos métodos tradicionais de avaliação, especialistas em usabilidade analisam a interação de cada usuário interagindo com a aplicação, para encontrar problemas de usabilidade. Esta análise depende do conhecimento e esforço desses especialistas para encontrar problemas na aplicação avaliada. Desse modo, os métodos tradicionais, se utilizados em grande escala de usuários, tornam-se demasiadamente caros devido a seus custos e tempo de execução. Outra característica importante das aplicações Web é sua constante evolução, o que necessita de avaliações de usabilidade periódicas e constantes, para verificar se alterações não prejudicam sua usabilidade. Da mesma forma, os métodos tradicionais de avaliação de usabilidade tornam-se demasiadamente caros, se utilizados em avaliações constantes da usabilidade de aplicações Web. Nesse contexto, esta tese buscou, na automatização do processo de avaliação de usabilidade, uma alternativa para diminuir as dificuldades mencionadas anteriormente em se avaliar a usabilidade de aplicações Web, especialmente em sua fase de manutenção. Assim, esta tese defende a hipótese de que, utilizando-se um método de avaliação de usabilidade fundamentado na captura e análise da interação de usuários de maneira remota e automatizada, é possível diminuir as dificuldades existentes nos métodos tradicionais na fase de manutenção de uma aplicação Web, possibilitando ainda: a análise da interação de usuários em campo e em grande escala de usuários; a identificação de padrões de interação dos usuários com a aplicação; uma avaliação com baixo custo de execução, favorecendo a realização de avaliações periódicas de usabilidade de uma aplicação Web. Neste sentido, esta tese apresenta o desenvolvimento do WebHint, um método remoto e automatizado de avaliação de usabilidade para aplicações Web. O método proposto nesta tese foi aplicado em três estudos de usabilidade que validaram o WebHint como uma alternativa viável para a realização de avaliações remotas e automatizadas de usabilidade de aplicações Web / Abstract: Observing users interacting with user interfaces is the basis of traditional usability evaluation methods as user tests and field observation. In spite of their popularity and efficiency in finding usability problems, these traditional methods are considered expensive, due to the costs of involving users in the evaluation, preparing the infrastructure and specially, due to the costs of executing the methods and analyzing the results. The quality of the results obtained with these methods depends on the users participating of the evaluation, who need to represent all the user's profiles of the evaluated application. In the Web, due to the diversity and distributed location of the users, it is difficult to obtain representative users. In traditional methods, usability experts analyze the behavior of each user interacting with the application in order to detect usability problems. This subjective analysis depends on the knowledge and work of the expert to find the problems. This way, the traditional methods became too expensive when it is necessary to involve high number of users in the evaluation. Another important aspect of Web applications is their frequent evolvement, which requires usability evaluations performed frequently to avoid usability problems caused by changes on the applications. The same way, the traditional methods are too expensive to be performed in a regular basis. In that context, this thesis proposes an automatic method for usability evaluation, as an alternative approach to deal with the difficulties mentioned above. This way, this thesis supports the hypothesis that is possible to decrease the difficulties regarding to the traditional methods through a usability evaluation method based on the automatic capture and analysis of user's interaction. Thus, this thesis, presents the development of the WebHint, a remote and automatic usability evaluation method for Web applications. The proposed method was applied in three usability studies, and their results validated the WebHint as a feasible alternative to perform remote and automatic usability evaluations of Web applications / Doutorado / Ciência da Computação / Doutor em Ciência da Computação

Für den Zugang zu grafischen Benutzungsoberflächen (GUIs) stehen blinden Menschen so genannte Screenreader und Braillezeilen zur Verfügung. Diese ermöglichen zwar das nicht-visuelle Wahrnehmen textueller Inhalte, allerdings kein effektives Arbeiten mit bildlichen Darstellungen. Neuartige taktile Flächendisplays können eine geeignete Lösung für den interaktiven Zugang zu tastbaren Grafiken darstellen und somit die Interaktionsmöglichkeiten blinder Benutzer im Umgang mit grafischen Anwendungen bereichern. Beispielsweise erlauben derartige Geräte nicht nur das Erkunden räumlicher Anordnungen, sondern darüber hinaus auch die kombinierte Ausgabe von Braille, Grafik und semi-grafischen Elementen. Um die deutlich größere Menge an gleichzeitig darstellbaren Informationen beherrschbar zu machen, sind neben entsprechenden Inhaltsaufbereitungen und Navigationsmechanismen auch geeignete Orientierungshilfen bereitzustellen. Im Rahmen der vorliegenden Arbeit wurde am Beispiel der BrailleDis Geräte der Metec AG, welche eine taktile Ausgabefläche von 120 mal 60 Stiften bereitstellen, untersucht, inwieweit flächige Brailledisplays blinden Menschen eine effektive und effiziente Bedienung grafischer Benutzungsoberflächen ermöglichen. Neben dem Zugang zur GUI selbst sowie dem Lesen von Texten stellt dabei insbesondere das Arbeiten mit Grafiken einen wichtigen Aspekt dar. Um die Bedienung auf einem taktilen Flächendisplay zu erleichtern, ist eine konsistente Organisation der Inhalte hilfreich. Hierfür wurde ein neuartiges taktiles Fenstersystem umgesetzt, welches die Ausgabe nicht nur in mehrere disjunkte Bereiche unterteilt, sondern auch verschiedene taktile Darstellungsarten unterstützt. Zur Systematisierung der Gestaltung und Evaluation derartiger taktiler Benutzungsoberflächen sowie der darin stattfindenden Benutzerinteraktionen wurde zunächst eine Taxonomie erarbeitet. Dabei wurden neben der Interaktion selber, welche durch die Ein-und Ausgabe sowie die Handbewegungen des Benutzers beschrieben werden kann, auch die Benutzerintention in Form von taktilen Elementaraufgaben sowie die technischen Spezifikationen des Geräts mit einbezogen. Basierend auf der Taxonomie wurden anschließend relevante Aspekte identifiziert, welche in mehreren Benutzerstudien mit insgesamt 46 blinden und hochgradig sehbehinderten Menschen untersucht wurden. Die betrachteten Untersuchungsfragen betrafen dabei einerseits die Effektivität der Ausgabe in Form verschiedener taktiler Ansichtsarten sowie die Eingabe und Erkundung durch den Benutzer, andererseits auch Aspekte zur Effizienz konkreter Interaktionstechniken. Als Ergebnis der einzelnen Studien wurden abschließend konkrete Empfehlungen zur Umsetzung von Benutzungsoberflächen auf flächigen Brailledisplays gegeben. Diese beinhalten insbesondere Aspekte zur Ergonomie von taktilen Flächendisplays, zur Anzeige von textuellen Inhalten, zur Darstellung und Interaktion mit grafischen Inhalten sowie zu Orientierungshilfen. Insgesamt konnte mit Hilfe der Benutzerstudien gezeigt werden, dass flächige Brailledisplays blinden Menschen einen effektiven und effizienten Zugang zu grafischen Benutzungsoberflächen ermöglichen. Verschiedene taktile Darstellungsarten können dabei das Lösen unterschiedlicher Aufgaben unterstützen. Generell erfordert die flächige Interaktion vom Benutzer allerdings auch die Erweiterung seiner konventionellen Erkundungs-und Eingabestrategien. Die Bereitstellung neuartiger Interaktionstechniken zur Unterstützung der Orientierung kann die Effizienz zusätzlich steigern. / Blind people normally use screen readers as well as single-lined refreshable Braille displays for accessing graphical user interfaces (GUIs). These technologies allow for a non-visual perception of textual content but not for an effective handling of visual illustrations. Novel two-dimensional tactile pin-matrix devices are an appropriate solution to interactively access tactual graphics. In this way, they can enrich the interaction possibilities of blind users in dealing with graphical applications. For instance, such devices enable the exploration of spatial arrangements and also combine output of Braille, graphics and semi-graphical elements. To make the high amount of simultaneously presented information perceivable and efficiently usable for blind users, an adequate preparation of content as well as adapted navigation and orientation mechanisms must be provided. In this thesis the BrailleDis devices of Metec AG, which have a tactile output area of 120 times 60 pins, were used. The goal was to investigate to what extent large pin-matrix devices enable blind people to use graphical user interfaces effectively and efficiently. Access to the GUI itself, reading text, and dealing with graphics are the main aspects of the application area of such devices. To facilitate the operation on a two-dimensional pin-matrix device a consistent organization of the content is helpful. Therefore, a novel tactile windowing system was implemented which divides the output area into multiple disjunctive regions and supports diverse tactile information visualizations. Moreover, a taxonomy was developed to systematize the design and evaluation of tactile user interfaces. Apart from interaction that can be described by input and output as well as hand movements, the taxonomy includes user intention in terms of interactive task primitives and technical specifications of the device. Based on the taxonomy, relevant aspects of tactile interaction were identified. These aspects were examined in multiple user studies with a total of 46 blind and visually impaired participants. The following research topics were considered during the user studies: 1. the effectiveness of diverse tactile view types (output), 2. user input and exploration, and 3. the efficiency of specific interaction techniques. As a result, practical recommendations for implementing user interfaces on two-dimensional pin-matrix devices were given. These recommendations include ergonomic issues of physical devices as well as design considerations for textual and graphical content as well as orientation aids. In summary, the user studies showed that two-dimensional pin-matrix devices enable blind people an effective and efficient access to graphical user interfaces. Diverse tactile information visualizations can support users to fulfill various tasks. In general, two-dimensional interaction requires the extension of conventional exploration and input strategies of users. The provision of novel interaction techniques for supporting orientation can help to increase efficiency even more.