Publications

Campos JC.  2005.  Model based web interfaces' analysis. HCI International 2005 - 11th International Conference on Human-Computer Interaction (posters section). Abstract0fcfd508e7e264007c000000.pdf

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.

Campos JC, Fernandes A.  2005.  Testing AudioBrowser. HCI International - 11th International Conference on Human-Computer Interaction (posters section). Abstracthciint05-ab_af.pdf

We are developing AudioBrowser, a browser for visually impaired users. This paper presents a usability analysis study that was carried out on the first version of the browser. Due to the lack of availability of visually impaired users not involved with the tool's design, we had to resort to simulate a visual impaired situation with regular sighted users. Although this may seem unrealistic we believe that this is actually a worst case scenario.The problems identified during this study are described, and proposals for the next version of the tool are put forward.

Mano A, Campos JC.  2005.  A study on usability criteria regarding interfaces for children. Interact 2005 Workshop on Child Computer Interaction: Methodological Research. :32-35. Abstractinteract05-kids.pdf

Building an application's interface is always an attempt to match the software functions with the users' mental model. This task is complicated enough when an adult is designing the interface to other adults. When the users are children, the challenge is harder still. How can the users' mental model be predicted? This communication deals with a study that aims to answer this question, going from the characteristics of the children cognitive thought to the discovery of efficient design guidelines for interfaces.

Teixeira L, Costa Ó, Pereira V, Leão CP, Soares F, Restivo M, Chouzal F, Mendes J, Campos JC.  2005.  Laboratórios virtuais: duas aplicações no ensino de engenharia. 7º Simpósio Internacional de Informática Educativa – SIIE. Abstractp479-teixeira.pdf

Este projecto insere-se no âmbito dos estágios curriculares de final de curso da licenciatura em Matemática e Ciências de Computação da Universidade do Minho e da disciplina de Laboratório de Automação do 5ºano da licenciatura de Engenharia Mecânica Faculdade de Engenharia da Universidade do Porto. O trabalho proposto, numa base de ensino/aprendizagem colaborativo e multidisciplinar, assenta também na prática assistido por projecto. Este projecto consiste no desenvolvimento de objectos de aprendizagem através da construção e disponibilização de simuladores e conteúdos de suporte em ambiente Web. Foram desenvolvidas aplicações baseadas em sistemas reais: medição e controlo do nível de um sistema de tanques em circuito fechado e medição da deformação de uma estrutura. Visa, também, a implementação dos sistemas experimentais, respectiva sensorização, actuação e controlo para integração num projecto de Laboratórios Remotos . Os Laboratórios Virtuais e os Laboratórios Remotos têm sido alvo de particular atenção no âmbito do ensino a distância, como meio complementar ao ensino tradicional ou na sua utilização integrada em redes de parceiros partilhando as capacidades laboratoriais distintas de diferentes instituições.

Campos JC.  2004.  The modelling gap between software engineering and human-computer interaction. ICSE Workshop: Bridging the Gaps II. :54-61. Abstracticse04.pdf

The theories and practices of software engineering and of human-computer interaction have, to a great extent, evolved separately. It seems obvious that the development of an interactive system would benefit from input from both disciplines. In practice, however, the communication between the two communities has been difficult. Models can be a particularly good tool for communication. For that to happen the differences between the models used by each community must first be identified and understood. This paper looks at the gaps between the models used by the software engineering and the human-computer interaction communities. It identifies where differences between these models can be found, and some aspects that need addressing in order to promote better communication.

Campos JC.  2004.  Análise de usabilidade baseada em modelos. Interação 2004 - 1a. Conferência Nacional em Interação Pessoa-Máquina. :171-176. Abstractint04.pdf

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 deve então ter em consideração os utilizadores e o contexto de utilização. Isto coloca problemas pois tipicamente os engenheiros de software não estão motivados, nem tem os conhecimentos necessários, para analisarem o sistema desta perspectiva. 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.

Fernandes A, Pereira JO, Campos JC.  2004.  Accessibility and Visually Impaired Users. ICEIS - Proceedings of the 6th International Conference on Enterprise Information Systems. 5:75-80. Abstracticeis04.pdf

Internet accessibility for the visually impaired community is still an open issue. Guidelines have been issued by the W3C consortium to help web designers to improve web site accessibility. However several studies show that a significant percentage of web page creators are still ignoring the proposed guidelines. Several tools are now available, general purpose, or web specific, to help visually impaired readers. But is reading a web page enough? Regular sighted users are able to scan a web page for a particular piece of information at high speeds. Shouldn't visually impaired readers have the same chance? This paper discusses some features already implemented to improve accessibility and presents a user feedback report regarding the AudioBrowser, a talking browser. Based on the user feedback the paper also suggests some avenues for future work in order to make talking browsers and screen readers compatible.

Mano A, Campos JC.  2004.  A study about usability criteria on computer interfaces for children. 1st Portuguese Forum of Experimental Psychology. Abstracthandout.pdf

This study's main goal is to produce a set of guidelines intended to aid a programmer who wishes to build a computer application targeted at children ranging from 5 to 7 years old.

Mano A, Campos JC.  2004.  Aplicação de um Cognitive Walkthrough - estudo de caso. Interação 2004 - 1a. Conferência Nacional em Interação Pessoa-Máquina. :256-258. Abstractint04-mano.pdf

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.

Campos JC, Harrison M, Loer K.  2004.  Verifying user interface behaviour with model checking. Verification and Validation of Enterprise Information Systems (VVEIS 2004). :87-96. Abstract10.1.1.131.5872.pdf

A large proportion of problems found in deployed systems relate to the user interface. This paper presents an approach to the verification of user interface models based on model checking. The approach is intended to be used early in design. The verification is concerned with behavioural aspects of the user interface and requires models that represent both the interactive aspects and also capture important features of the context to allow restrictions of behaviour to those that conform to appropriate human and environmental constraints. A tool suite to support the approach is under development and is described. Future work directions are put forward.

Campos JC, Doherty G.  2003.  Reasoning about Dynamic Information Displays. II3 Spring Days Workshop. 2844:288-302. Abstracti3sd01-cfcs.pdf

With increasing use of computing systems while on the move and in constantly changing conditions, whether it is via mobile devices, wearable computers or embedded systems in the environment, time plays an increasingly important role in interaction. The way in which information is represented in an interface is fundamental to interaction with it, and how the information is used in the users tasks and activities. Dynamic representations where the user must perceive changes in the information displayed over time pose a further challenge to the designer. Very often this information is integrated with information from the environment in the performance of the user’s tasks. The diminutive size and limited display capabilities of many ubiquitous and mobile computing devices further motivate careful design of these displays. In this paper we look at how time can be taken into account when reasoning about representational issues from the early stages of design. We look at a model which can be used to reason about these issues in a structured fashion, and apply it to an example.

Campos JC, Harrison M.  2003.  From HCI to Software Engineering and back. Bridging the Gaps Between Software Engineering and Human-Computer Interaction, ICSE '2003 workshop. :49-56. Abstractcamposh03.pdf

Methods to assess and ensure system usability are becoming increasingly important as market edge becomes less dependent on function and more dependent on ease of use, and as recognition increases that a user’s failure to understand how an automated system works may jeapordise its safety. While ultimately only deployment of a system will prove its usability, a number of approaches to early analysis have been proposed that provide some ability to predict the usability and human-error proneness of the fielded system. The majority of these approaches are designed to be used by human factors specialists, require specific expertise that does not fall within the domain of software engineering and fall outside standard software development life cycles. However, amongst this number, some rigorous mathematical methods have been proposed as solutions to the more general problem of ensuring quality of system designs citations both in terms of the broader software engineering agenda and in terms of their effectiveness for usability analysis, the opportunities that they offer and discusses what might be done to make them more acceptable and effective. The paper positions those methods that have been effective against less formal usability analysis methods.

Campos JC.  2003.  Using task knowledge to guide interactor specifications analysis. Interactive Systems: Design, Specification and Verification - DSV-IS. 2844:171-186. Abstract29.pdf

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.

Campos JC.  2003.  Uma abordagem formal À Engenharia da Usabilidade. CLIHC - Conference Proceedings. :17-28. Abstractclihc03.pdf

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 usability issues. In this context, the application 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.

Campos JC, Harrison M.  2001.  Model Checking Interactor Specifications. ASE - Automated Software Engineering. 8(3):275-310. Abstractcamposh01.pdf

Recent accounts of accidents draw attention to "automation surprises'' that arise in safety critical systems. An automation surprise can occur when a system behaves differently from the expectations of the operator. Interface mode changes are one class of such surprises that have significant impact on the safety of a dynamic interactive system. They may take place {\em implicitly} as a result of other system action. Formal specifications of interactive systems provide an opportunity to analyse problems that arise in such systems. In this paper we consider the role that an {\em interactor} based specification has as a partial model of an interactive system so that mode consequences can be checked early in the design process. We show how interactor specifications can be translated into the SMV model checker input language and how we can use such specifications in conjunction with the model checker to analyse potential for mode confusion in a realistic case. Our final aim is to develop a general purpose methodology for the automated analysis of interactive systems. This verification process can be useful in raising questions that have to be addressed in a broader context of analysis.