Publications

Campos JC, Fayollas C, Martinie C, Navarre D, Palanque P, Pinto M.  2016.  Systematic Automation of Scenario-Based Testing of User Interfaces. In Proceedings of the 8th ACM SIGCHI Symposium on Engineering Interactive Computing Systems, pages 138-148. Abstractfp0148-paper.pdf

Ensuring the effectiveness factor of usability consists in ensuring that the application allows users to reach their goals and perform their tasks. One of the few means for reaching this goal relies on task analysis and proving the compatibility between the interactive application and its task models. Synergistic execution enables the validation of a system against its task model by co-executing the system and the task model and comparing the behavior of the system against what is prescribed in the model. This allows a tester to explore scenarios in order to detect deviations between the two behaviors. Manual exploration of scenarios does not guarantee a good coverage of the analysis. To address this, we resort to model-based testing (MBT) techniques to automatically generate scenarios for automated synergistic execution. To achieve this, we generate, from the task model, scenarios to be co-executed over the task model and the system. During this generation step we explore the possibility of including considerations about user error in the analysis. The automation of the execution of the scenarios closes the process. We illustrate the approach with an example.

Harrison M, Campos JC, Ruksenas R, Curzon P.  2016.  Modelling information resources and their salience in medical device design. In Proceedings of the 8th ACM SIGCHI Symposium on Engineering Interactive Computing Systems, pages 194-203. Abstractocbeics16pub.pdf

The paper describes a model that includes an explicit description of the information resources that are assumed to guide use, enabling a focus on properties of "plausible interactions". The information resources supported by an interactive system should be designed to encourage the correct use of the system. These resources signpost a user's interaction, helping to achieve desired goals. Analysing assumptions about information resource support is particularly relevant when a system is safety critical that is when interaction failure consequences could be dangerous, or walk-up-and-use where interaction failure may lead to reluctance to use with expensive consequences. The paper shows that expressing these resource constraints still provides a wider set of behaviours than would occur in practice. A resource may be more or less salient at a particular stage of the interaction and as a result potentially overlooked. For example, the resource may be accessible but not used because it does not seem relevant to the current goal. The paper describes how the resource framework can be augmented with additional information about the salience of the assumed resources. A medical device that is in common use in many hospitals is used as illustration.

Couto R, Ribeiro AN, Campos JC.  2016.  Validating an Approach to Formalize Use Cases with Ontologies. Proceedings of the 13th International Workshop on Formal Engineering Approaches to Software Components and Architectures, FESCA@ETAPS 2016, Eindhoven, The Netherlands, 3rd April 2016.. :1–15. Abstract1603.08632.pdf

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Abade T, Campos JC, Moreira R, Silva CC, Silva JL.  2015.  Immersiveness of Ubiquitous Computing Environments Prototypes: A case study. Lecture Notes in Computer Science. 9189 Abstract15-dapi-abadecmss-sarch.pdf

The development of ubiquitous computing (ubicomp) environments raises several challenges in terms of their evaluation. Ubicomp virtual reality prototyping tools enable users to experience the system to be developed and are of great help to face those challenges, as they support developers in assessing the consequences of a design decision in the early phases of development. Given the situated nature of ubicomp environments, a particular issue to consider is the level of realism provided by the prototypes. This work presents a case study where two ubicomp prototypes, featuring different levels of immersion (desktop-based versus CAVE-based), were developed and compared. The goal was to determine the cost/benefits relation of both solutions, which provided better user experience results, and whether or not simpler solutions provide the same user experience results as more elaborate one.

Lamas J, Silva CC, Silva M, Mouta S, Campos JC, Santos J.  2015.  Measuring end-to-end delay in real-time auralisation systems. Euronoise – 10th European Congress and Exposition on Noise Control Engineering Abstractend2enddelay_euronoise2015.pdf

One of the major challenges in the development of an immersive system is handling the delay between the tracking of the user’s head position and the updated projection of a 3D image or auralised sound, also called end-to-end delay. Excessive end-to-end delay can result in the general decrement of the “feeling of presence”, the occurrence of motion sickness and poor performance in perception-action tasks. These latencies must be known in order to provide insights on the technological (hardware/software optimization) or psychophysical (recalibration sessions) strategies to deal with them. Our goal was to develop a new measurement method of end-to-end delay that is both precise and easily replicated. We used a Head and Torso simulator (HATS) as an auditory signal sensor, a fast response photo-sensor to detect a visual stimulus response from a Motion Capture System, and a voltage input trigger as real-time event. The HATS was mounted in a turntable which allowed us to precisely change the 3D sound relative to the head position. When the virtual sound source was at 90º azimuth, the correspondent HRTF would set all the intensity values to zero, at the same time a trigger would register the real-time event of turning the HATS 90º azimuth. Furthermore, with the HATS turned 90º to the left, the motion capture marker visualization would fell exactly in the photo-sensor receptor. This method allowed us to precisely measure the delay from tracking to displaying. Moreover, our results show that the method of tracking, its tracking frequency, and the rendering of the sound reflections are the main predictors of end-to-end delay.

Almeida D, Campos JC, Saraiva JA, Silva JC.  2015.  Towards a catalog of usability smells. SAC - Proceedings of the 30th Annual ACM Symposium on Applied Computing. Abstractsac2015_1.pdf

This paper presents a catalog of smells in the context of interactive applications. These so-called usability smells are indicators of poor design on an application's user interface, with the potential to hinder not only its usability but also its maintenance and evolution. To eliminate such usability smells we discuss a set of program/usability refactorings. In order to validate the presented usability smells catalog, and the associated refactorings, we present a preliminary empirical study with software developers in the context of a real open source hospital management application. Moreover, a tool that computes graphical user interface behavior models, giving the applications' source code, is used to automatically detect usability smells at the model level.

Machado M, Campos JC, Couto R.  2015.  MODUS: uma metodologia de prototipagem de interfaces baseada em modelos. Inforum 2015: Atas do 7º Simpósio Nacional de Informática. :17-32.inforum-2015.pdf
Harrison M, Campos J, Masci P, Curzon P.  2015.  Templates as heuristics for proving properties of medical devices. 5th EAI International Conference on Wireless Mobile Communication and Healthcare - "Transforming healthcare through innovations in mobile and wireless technologies". antennatemplatesv5-final.pdf
Campos JC, Silva JL, Harrison M.  2015.  Supporting the Design of an Ambient Assisted Living System Using Virtual Reality Prototypes. Ambient Assisted Living. ICT-based Solutions in Real Life Situations. 9455:49-61.authorsversion.pdf
Sousa M, Campos JC, Alves M, Harrison M.  2014.  Formal Verification of Safety-Critical User Interfaces: a space system case study. Formal Verification and Modeling in Human Machine Systems: Papers from the AAAI Spring Symposium. :62-67. Abstract7722-34384-1-pb.pdf

Safe operation of safety critical systems depends on appropriate interactions between the human operator and the computer system. Specification of such safety-critical systems is fundamental to enable exhaustive and automated analysis of operator system interaction. In this paper we present a structured, comprehensive and computer-aided approach to formally specify and verify user interfaces based on model checking techniques.

Couto R, Ribeiro AN, Campos JC.  2014.  Application of Ontologies in Identifying Requirements Patterns in Use Cases. 11th International Workshop on Formal Engineering approaches to Software Components and Architectures (FESCA. 147:62–76. Abstractfesca_2014.pdf

Use case specifications have successfully been used for requirements description. They allow joining, in the same modeling space, the expectations of the stakeholders as well as the needs of the software engineer and analyst involved in the process. While use cases are not meant to describe a system's implementation, by formalizing their description we are able to extract implementation relevant information from them. More specifically, we are interested in identifying requirements patterns (common requirements with typical implementation solutions) in support for a requirements based software development approach. In the paper we propose the transformation of Use Case descriptions expressed in a Controlled Natural Language into an ontology expressed in the Web Ontology Language (OWL). OWL's query engines can then be used to identify requirements patterns expressed as queries over the ontology. We describe a tool that we have developed to support the approach and provide an example of usage.

Campos JC, Arcuri A, Fraser G, Abreu R.  2014.  Continuous Test Generation: Enhancing Continuous Integration with Automated Test Generation. Proceedings Automated Software Engineering (ASE). Abstractase14_ctg.pdf

In object oriented software development, automated unit test generation tools typically target one class at a time. A class, however, is usually part of a software project consisting of more than one class, and these are subject to changes over time. This context of a class offers significant potential to improve test generation for individual classes. In this paper, we introduce Continuous Test Generation (CTG), which includes automated unit test generation during continuous integration (i.e., infrastructure that regularly builds and tests software projects). CTG offers several benefits: First, it answers the question of how much time to spend on each class in a project. Second, it helps to decide in which order to test them. Finally, it answers the question of which classes should be subjected to test generation in the first place. We have implemented CTG using the EVOUITE unit test generation tool, and performed experiments using eight of the most popular open source projects available on GitHub, ten randomly selected projects from the SF100 corpus, and five industrial projects. Our experiments demonstrate improvements of up to +58% for branch coverage and up to +69% for thrown undeclared exceptions, while reducing the time spent on test generation by up to +83%.

Couto R, Ribeiro AN, Campos JC.  2014.  The Modelery: A Collaborative Web Based Repository. 14th International Conference on Computational Science and Its Applications (ICCSA 2014). 8584 Abstracticcsa_2014.pdf

Software development processes are known to produce a large set of artifacts such as models, code and documentation. Keeping track of these artifacts without supporting tools is not easy, and making them available to others can be even harder. Standard version control systems are not able to solve this issue. More than keeping track of versions, a system to help organize and make artifacts available in meaningful ways is needed. In this paper we review a number of alternative systems, and present the requirements and the implementation of a collaborative web repository which we developed to solve this issue.

Couto R, Ribeiro AN, Campos JC.  2014.  A study on the viability of formalizing Use Cases. 9th International Conference on the Quality of Information and Communications Technology (QUATIC). Abstract6133a130.pdf

Use case scenarios are known as powerful meansfor requirements specification. On th e one hand, they join in the same modeling space the expectations of the stakeholders and the needs of the developers involved in the process. On the other hand, they describe the desired high level functionalities. By formalizing these descriptions we are able to extract relevant informations from them. Specifically, we are interested in identifying requirements patterns (common requirements with typical implementation solutions) in support for a requirements based software development approach. This paper addresses the transformation of use case descriptions expressed in a Controller Natural Language into an ontology expressed in the Web Ontology Language (OWL), as well as the query process for such information. It reports on a study aimed at validating our approach and our tool with real users. A preliminary set of results is discussed.

Silva CE, Campos JC.  2014.  Characterizing the Control Logic of Web Applications' User Interfaces. In Computational Science and Its Applications - ICCSA 2014. 8584:263–276. Abstracticcsa_final.pdf

On order to develop an hybrid approach to the Reverse Engineer of Web applications, we need rst to understand how much of the control logic of the user interface can be obtained from the analysis of event listeners. To that end, we have developed a tool that enables us to perform such analysis, and applied it to the implementation of the one thousand most widely used Websites (according to Alexa Top Sites). This paper describes our approach for analyzing the user interface layer of those Websites, and the results we got from the analysis. The conclusions drawn from the exercise will be used to guide the development of the proposed hybrid reverse engineering tool.