Model based web interfaces' analysis

Tools exist that look at the usability of sites from a static perspective – for example, looking for broken links. Other tools analyse web server's logs to understand how users behave when using the site. While these tools are helpful, they can only be applied after development and deployment. This paper investigates how a model checking based approach can be applied to web sites' design to reason about their behavioral properties from the early stages of development. The goal is that analysis of possible interactions between users and a site might be performed before actual development and deployment of the site

Integrating automated verification into interactive systems development

Our field of research is the application of automated reasoning techniques during interactor based interactive systems development. The aim being to ensure that the developed systems embody appropriate properties and principles. In this report we identify some of the pitfalls of current approaches and propose a new way to integrate verification into interactive systems development.Fundação para a Ciência e a Tecnologia - PRAXIS XXI/BD/9562/96

Uma abordagem formal à engenharia da usabilidade

A qualidade dos sistemas interactivos pode ser medida em termos da sua usabilidade. Abordagens empíricas à avaliação procuram avaliar os sistemas sob condições reais de utilização mas, tipicamente, são dispendiosos. Abordagens analíticas à análise de modelos tem sido propostas como um meio de raciocinar sobre questões de usabilidade desde as fases iniciais do desenvolvimento. Estas abordagens socorrem-se de modelos para focarem a análise em aspectos específicos da usabilidade. Neste contexto, a utilização de notações e ferramentas (matematicamente) formais tem sido proposta. Este artigo apresenta uma abordagem integrada à verificação de sistemas interactivos. A análise tanto pode ser realizada apenas tendo em conta o comportamento do artefacto, como permite a integração de um modelo de tarefas por forma a restringir o comportamento do artefacto a um subconjunto adequado de todos os seus possíveis comportamentos.The quality of an interactive system can be measured in terms of its usability. Empirical approaches to usability evaluation attempt to assess the system under real usage conditions. This type of approach can be very expensive. Analytical approaches have been proposed as a means of reasoning about usability issues from early in development. These approaches use models to focus the analysis in specific usuability issues. In this context, the aplication of (mathematically) formal notations and tools has been proposed.This paper presents a formal approach to the analysis of interactive systems. The analysis can be carried out taking into account all possible behaviours of the device, or it can be guided by the tasks the device is supposed to support

High assurance interactive computing systems

If interactive computing systems development is to be considered an engineering discipline, we need methods and tools to help us reason about and predict the quality of systems, from early in the design process. This paper provides a brief overview of work we have been carrying out in the general area of evaluating and ensuring the quality of interactive computing. systems. Some of the work currently being carried out is also discussed. Discussed approaches range from the formal verification of user interface models through model checking, to the reverse engineering and model based testing of implemented interactive computing systems

Using task knowledge to guide interactor specifications analysis

This paper looks at how to extend the type of analysis that can be done using interactor based models of interactive systems, the i2smv tool, and SMV. Originally, the type of analysis performed with i2smv/SMV was concerned with the exhaustive exploration of all possible behaviours of a device, with little direct consideration of the tasks it should support. The paper investigates how task models can be introduced into the approach in order to extend the range of properties that can be analysed

Análise de usabilidade baseada em modelos

A norma ISO DIS 9241-11 define usabilidade de um sistema como a eficácia, eficiência e satisfação com que utilizadores determinados atingem objectivos determinados em ambientes específicos. A análise de usabilidade de um sistema interactivo deve então ter em consideração os utilizadores e o contexto de utilização do mesmo. Torna-se, portanto, necessário recorrer a peritos na área da Interacção Humano-Computador para ter em consideração factores de usabilidade. Neste artigo apresenta-se a arquitectura de uma ferramenta que suporta uma abordagem ao desenvolvimento de sistemas interactivos em que se procura facilitar a comunicação entre as comunidades da Interacção Humano-Computador e da Engenharia de Software

Cognitive walkthroughs in the evaluation of user interfaces for children

This paper describes a case-study, dealing with the application of the cognitive walkthrough as a method of evaluating an interface built for children. We performed the walkthrough and tested the interface with children aged between 5 and 7 years old. Given our goals and the scope of this study, the cognitive walkthrough proved as a reliable source of indications about usability problems on an interface aimed at children

Pattern-based analysis of automated production systems

As formal verification tools gain popularity, the problem arises of making them more accessible to engineers. A correct understanding of the logics in which properties are expressed is needed in order to guarantee that properties correctly encode the intent of the verification process. Writing appropriate properties, in a logic suitable for verification, is a skilful process. Errors in this step of the process can create serious problems since a false sense of security if gained with the analysis. However, when compared to the effort put into developing and applying modelling languages, little attention has been devoted to the process of writing properties that accurately capture verification requirements. This paper illustrates how a collection of property patterns, and its tool support, can help in simplifying the process of generating logical formulae from informally expressed requirements.(undefined

Aplicação de um cognitive walkthrough: estudo de caso

Esta comunicação é uma tentativa de sistematizar a aplicação de um método de análise de usabilidade: o cognitive walkthrough. Pode então ser utilizada como um tutorial, apresentando um exemplo da aplicação do método a uma situação prática