Using GOMS to predict the usability of user interfaces of small off-the-shelf software products

The design of user interfaces and how usable they are, are both important research topics in computer science. This thesis is a research effort aimed at exploring the whole concept of usability and measuring the quality of a user interface in terms of how usable it is. Usability means how easy a system can be learned and used. In order to have usable products, they must be initially designed with usability in mind. A survey of methods for designing user interfaces which incorporate usability are outlined and they include some or all of the principles for designing for usability, proposed by various authors. Evaluating the quality of existing interfaces can be done by various methods.The method used in this dissertation is the GOMS (goals, operators, methods and selection rules) approach. This model was initially proposed by [Card, Moran & Newell 83] and the approach is based on constructing an explicit model of the user's procedural knowledge, entailed by a particular system design. [Kieras & Poison 85] expanded this model to suggest that quantitive measures defined on this explicit representation of the user's knowledge can predict important aspects of usability. The predictions are obtained from a computer simulation model of the user's procedural knowledge that can actually execute the same tasks as the user. To test the reliability and accuracy of the GOMS model predictions, the author carried out a pseudo-experiment on four inexperienced users using two different types of word-processors. The actual results from the experiment were compared with the GOMS predictions.The GOMS model was found to have some limitations and some enhancements to the approach are proposed. It was also found that the experiment had some limitations and improvements for a better experiment are proposed

Os meus amigos sentimentos

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.A criança é um ser que busca naturalmente fontes de entretenimento e diversão. A par da crescente influência dos dispositivos móveis nas nossas vidas, é natural que também as crianças mostrem interesse nestes computadores de bolso que se mostram cada vez mais indissociáveis do ser humano. Apesar de existirem categorias de aplicações móveis (apps) destinadas a crianças, a maioria destas são dedicadas a áreas como as línguas, ciências e matemática, ficando penalizadas áreas cruciais para o desenvolvimento da criança em idade pré-escolar como a psicologia, áreas do autoconhecimento e dos sentimentos. Desta lacuna surge a necessidade de criar uma aplicação destinada a crianças dos 4 aos 6 anos, com personagens e cenários com as quais as crianças se possam identificar, estimulando a conversa entre pais/educadores e crianças sobre medos, birras e ciúmes. Através de cenários interativos, a criança irá ajudar os “amigos sentimentos” a ultrapassar os medos do Medo Alfredo, as birras do Quero-Tudo e os ciúmes da Zanga Franga. Foram entrevistadas dez crianças acerca das personagens, cenários e histórias, que responderam com grande entusiasmo ao universo dos “amigos sentimentos”.ABSTRACT: Children are natural seekers of entertainment and fun. Along with the growing influence of mobile devices on our daily lives, children show growing interest in these pocket computers, becoming inseparable from them. Although there are categories of mobile apps meant for children, most of them are dedicated to language, science and mathematics, leaving behind crucial areas for the preschooler children’s development such as psychology, self-knowledge and feelings. This gap in the mobile app industry arises the need to develop a mobile app for children from age 4 to 6, with characters and scenarios wherewith children will relate to, stimulating conversation between parents/tutors with children about their fears, tantrums and jealousy. Through interactive scenarios, children will help their “feeling friends” to overcome the fears of Medo Alfredo, the tantrums by Quero-Tudo and Zanga Franga’s jealousy. Ten children were interviewed on the characters, scenarios and stories, who responded with great enthusiasm to the world of the “feeling friends”.N/

Mobile information system adoption and use: beliefs and attitudes in mobile context

During the last decades scholars and practitioners have been interested in the reasons why users either accept or reject Information Systems (IS). Users' perceptions of information technology have mainly been studied from acceptance, success, or usability perspectives. Although these research approaches have provided valuable information, they all have a limited view. Thus, there is a need for an integrated framework that fulfills the gaps between different approaches. In this study the acceptance and use of mobile systems are analyzed by combining the results of different disciplines. The main result of the study is a new model for Mobile IS Adoption and Use (MISAU). It integrates the elements of technology acceptance, information system success, and usability studies into a single model. As information system acceptance must always be analyzed in context of use, MISAU is based on the mobile service supply chain. The main differences between stationary and mobile systems can be found in network performance and usability of mobile devices. MISAU serves as a framework for case studies in which the effects of these special characteristics on users' perceptions are analyzed. The results of the study indicate that the ever-increasing transmission speeds of mobile networks are not alone adequate to increase the use of mobile services. Perceived quality of service is an outcome of multiple factors. The successful implementation of a mobile IS requires high quality in all elements of service supply chain (i.e. end-user devices, networks, and services). The small size of mobile devices is a serious threat to usability - especially to text entry and navigation within an application. Further studies are still needed in these sectors

Learnability makes things click : a grounded theory approach to the software product evaluation

The aim of this doctoral dissertation is to investigate the phenomenon of learnability more deeply in order to better understand the learnability process. Grounded theory was used to determine the ground concepts based on fifteen users’ (N=15) actions (N=1836) in the WebCT Campus Edition’s virtual environment. Based on this study, the phenomenon of learnability and the learnability process is understood in greater detail and defined from the human centric of view, where the human being is the key actor. This doctoral dissertation answers the following research problem: 1. How learnable is the WebCT Campus Edition’s virtual environment? 2. How can the phenomenon of learnability be defined in a new way? The WebCT Campus Edition virtual environment’s learnability was measured with performance time and directions of action. In addition, the traditional learnability metrics of performance time and direction of users’ actions was used to verify the theoretical model of learnability and its nonlinearity. The result of this study showed that the variety of the WebCT Campus Edition’s learnability was higher between the individual users than it was between the different tasks. Therefore, the variety of task difficulty, i.e. the complexity or easiness of the different part of the user interface, have less influence on learnability in the WebCT Campus Edition than do the individual users’characteristics. Thus, the research results confirm the results found in earlier studies, where two important issues for usability evaluation and therefore evaluation on learnability, are the tasks and users individual characteristics. The theoretical model of learnability with following phases of information search, data collection, knowledge management, knowledge form, knowledge build and the result of action were determined from data. The theoretical model of learnability and its main patterns of a) data collection-information search, b)knowledge build-knowledge form and c) information searchknowledge management proves that learnability is a non-linear process. Therefore, the phenomenon of learnability cannot purely be defined by the separate properties of learnability, i.e. the properties of a user interface and a progressively enhanced linear process illustrated with learning curves. The theoretical model of learnability is one of the rare models of learnability that is based on empirical data. The use of grounded theory methodology means that the phenomenon of learnability is studied through tacit knowledge, i.e. through users’ real actions and though explicit knowledge, the users cognitive processes during interaction i.e. the phenomenon of learnability is approached from the holistic point of view, where the phenomenon of learnability is seen as one holistic process. Thus triangulation, where the phenomenon is interpreted through several split case studies are therefore unnecessary in this research setting. In conclusion, too many studies are still conducted in a laboratory situation using traditional methodological paradigms. More learnability studies with new methodological approaches in the natural environments are needed were the human, learning and non-linear process of learnability are in focus. It is important to understand more deeply the process of learnability and investigate more in greater detail the key elements that enhance learnability and on the other hand, cause learnability problems for users. Finally, based on the theoretical models of learnability, we can develop tools for the commercial user interface world in order to measure and test the learnability process more precisely and better understand how skills are actually learnt and how “to click” learnability

Evaluating Feature Checklists as a Measurement Instrument in Human-Computer Interaction

This thesis is concerned with the development and assessment of a measurement tool for use in the field of Human-Computer Interaction (HCI); the instrument is known as the Feature Checklist (FC). The FC consists of a list of features of the user interface such as menu commands, against which are a few columns each asking a particular question. A series of seven studies were conducted in which the development of FCs progressed in a logical manner. Study 1 demonstrated that FCs were a more accurate and valid instrument compared with simple open-response questionnaires for asking users about their recent usage of menu commands, and had an accuracy of 87%. Studies 2 and 3 attempted to increase the accuracy of FCs by improving their visual layout. Study 4 demonstrated that FCs could provide additional information (i.e. other than frequency of usage) and that this additional information was also accurate. Study 5 replicated the findings of study 4 in an HCI setting and also provided evidence to suggest that command names are a more suitable way of listing features on the F.C. than semantic descriptions of commands' functions. Study 6 demonstrated the way in which FCs could be applied to HCI evaluation and assessed the cost to the user of completing a FC. Finally study 7 employed FCs in a "real-life", industrial setting. Throughout the thesis an attempt is made to relate the findings of each study to important research on human memory, in order to understand more fully the processes involved in FCs; the relevance of different theories of human memory are discussed. The results suggested that FCs provide accurate and valuable information about such things as: usage levels of interface features; user knowledge of the existence and function of interface features; and user estimates of the usefulness of interface features. As such, it is proposed that FCs are a useful addition to the area of HCI evaluation

La projection d'usage des TICs : la composition de fictions axiomatiques au service de la recherche technologique

Innovation is today a major and strategic asset for organisations that compete in a hypercompetitive world (D'Avenir & Gunther, 1994). They are trying to face these new challenges, by using a diversity of “expert systems” typical of our « advanced modernity » (Giddens, 1990). Amongst those, boosting R&D activities is major inputs that demand the use of different expertises. Speculative researches for innovation are one of them. They take place in the “Fuzzy Front End” of innovation, a place where the construction of the social reality of invention is made : its usage, or to be more precise, its projection. Our thesis examines these knowledge-producing technologies and tries to make understable the policies at work, the performance of embedded collectives on the innovation itself, and on themselves, and the arrangements made during this process. Our work in the Grenoble industrial area and collaboration with the CEA-LETI helped us to propose an understanding of these projections as compositions of axiomatic fictions for technological research. Analysing the concept of usage, we highlight its careers and the mutation of associated practices. Interrogating one form of projection, the scenario, we show the links that lie between fiction and perfomativity. By leaning on the project mutating components, we demonstrate the axiomatic character of the projection, understood as a form of answer made to a social demand that comes from different places, and whose necessity of actionnable knowledge is solved by composing with moving data.L'« hypercompétitivité » (D'Avenir & Gunther, 1994) qui caractérise notre environnement économique contemporain fait de l'innovation une préoccupation stratégique pour les organisations. Celles-ci tentent de répondre à cette injonction par le recours à une multitude de « systèmes experts », caractéristique de la « modernité avancée » (Giddens, 1990). Parmi ceux-ci, la stimulation des activités de R&D est reconnue comme une contribution majeure qui nécessite l'utilisation croissante de champs d'expertises variés. C'est dans ce contexte que les sciences sociales sont mobilisées comme forme d'expertise contributives des « recherches spéculatives pour l'innovation » (Stewart & Claeys, 2009). Ces recherches interviennent en amont de processus d'innovation, en un lieu nommé « Fuzzy Front End » (Smith & Reinertsen, 1995), lieu dans lequel se forge la construction de la réalité sociale de l'invention : son usage ou plutôt sa projection. Notre thèse s'interroge sur ces technologies de production de connaissances que sont les projections d'usage et ambitionne de rendre intelligibles les politiques qu'elles mettent en oeuvre, la performance des collectifs mobilisés sur les recherches et sur eux-mêmes ainsi que les arrangements déployés par les acteurs durant ces processus. Notre immersion dans le tissu industriel grenoblois, et en particulier dans l'environnement du CEA-LETI, nous a permis de proposer une lecture des projections d'usage comme des compositions de fictions axiomatiques au service de la recherche technologique. En scrutant le concept d'usage, nous mettons en lumière les carrières empruntées par celui-ci et les mutations des pratiques associées. En interrogeant l'une des formes de la projection d'usage, le scénario, nous mettons en évidence les liens entre performativité et recours à la fiction. En interrogeant les mutations des composantes du projet, nous démontrons le caractère axiomatique des projections, en tant que forme de réponse à une demande sociale qui émane de plusieurs endroits et dont l'exigence de production de savoirs actionnables nécessite de composer avec des données en mouvement