Heloísa Vieira da Rocha

Visual structures for image browsing

Content-Based Image Retrieval (CBIR) presents several challenges and has been subject to extensive research from many domains, such as image processing or database systems. Database researchers are concerned with indexing and querying, whereas image processing experts worry about extracting appropriate image descriptors. Comparatively little work has been done on designing user interfaces for CBIR systems. This, in turn, has a profound effect on these systems since the concept of image similarity is strongly influenced by user perception. This paper describes an initial effort to fill this gap, combining recent research in CBIR and Information Visualization, studied from a Human-Computer Interface perspective. It presents two visualization techniques based on Spiral and Concentric Rings implemented in a CBIR system to explore query results. The approach is centered on keeping user focus on both the query image, and the most similar retrieved images. Experiments conducted so far suggest that the proposed visualization strategies improves system usability.

Promídia: produção de vídeos digitais no contexto educacional

Nos dias de hoje a producao de videos digitais e uma atividade muito popular, principalmente entre criancas e adolescentes, como se observa pelo sucesso que fazem os sites que permitem disponibilizar videos na Internet. Apesar de geralmente ser desenvolvida visando o lazer e o entretenimento essa atividade tem grande potencial educacional. Tal potencial pode ser melhor explorado se levarmos em conta as caracteristicas das atividades que compoem o processo de producao de videos propriamente dito, tais como: desenvolvimento da sinopse, elaboracao do roteiro, elaboracao do storyboard, edicao, etc. Essas atividades, no entanto,requerem softwares que possam dar suporte a sua execucao e, em um contexto educacional, possam favorecer a visao geral de todo o processo de producao. Com o objetivo de favorecer e estimular a producao de videos como atividade educacional desenvolvemos o prototipo do Promidia que tem como objetivos: (i) auxiliar seus usuarios na criacao e elaboracao das principais etapas do processo de producao de videos, (ii) favorecer a visao global e a compreensao de todo o processo. Dois testes foram realizados com o Promidia, com usuarios com perfis diferentes, para se observar/analisar tanto questoes de usabilidade quanto questoes educacionais. Os resultados mostraram uma excelente aceitacao do prototipo e confirmaram o potencial da producao de video como atividade de ensino-aprendizagem.

Towards an approach for multi-device interface design

This paper proposes an approach for multi-device interface design that extends pre-designed interfaces keeping the original application conceptual model without loosing its usability, The proposal reinterprets general aspects of well known Human-Computer Interaction (HCI) lifecycle models and can be extended to the design of any interactive product. When validated through a simple transformation between a large and a small screen interface in an HCI domain, it shall point to a much less maintenance cost/complexity and a better usability, ensuring the users satisfaction.

A Ubiquitous, Pen-Based And Touch Classroom Response System Supported By Learning Styles

The Active Learning Model (ALM) is an educational model which proposes that students should participate, along with the teacher, as direct agents of their learning process. Computer systems created to implement and support the ALM are known as Classroom Response Systems (CRS). The CRS, usually supported by traditional pen-based Tablet PCs, allow the teacher to propose activities and exercises to students, receive back their answers, discuss the results and provide feedback.

A Case Study of the Development of e-Learning Systems Following a Component-based Layered Architecture

The development of flexible, reusable and interoperable LMSs has increasingly attracted the attention of the e-learning community. Considering these issues, the TIDIA-Ae project has been proposing a component-based solution for LMSs development. This article presents a development case study according to the TIDIA-Aes component-based architecture, whose activity was the development of the Portfolio and Weblog tools. The main artifacts obtained in the development process, the solutions adopted for the open issues and the main learned lessons are presented.

Analyzing user interaction logs to evaluate the usability of Web applications

In this paper we describe a usability study carried out using the WebHint method to analyze the usability of four Web applications. The method is based on remote and automatic capture, and semi-automatic analysis of users interaction. The experiment and its results show how the method can be used for analyzing the behavior of users interacting with online applications, in order to obtain a comprehensive view about the usability of these applications.

Discovering and analyzing patterns of usage to detect usability problems in web applications

In this paper we describe two usability studies in which the interaction of users with an online application was remotely and automatically captured and analyzed. The usability studies were performed using the WebHint method for usability analysis of web applications. We evaluate two different versions of the application in order to observe the applicability of the method for successive usability analysis. The results show how the WebHint method can be used as an alternative approach to carry out successive evaluations of the usability of an application in order to analyze the evolution of different versions of its interface.

Ferramenta de apoio para o aprendizado ativo usando dispositivos com caneta eletronica

Atualmente existe uma tendencia cada vez maior para a inclusao de dispositivos computacionais em sala de aula, disponibilizados com o intuito de melhorar o aprendizado e as praticas de ensino. Entretanto, o uso desses dispositivos nao deve ser feito de forma indiscriminada, devendo ser, ao contrario, fundamentado em praticas e modelos educacionais previamente elaborados e validados. Um desses modelos e o denominado aprendizado ativo, construtivista por natureza, cujo objetivo e permitir aos estudantes terem um papel ativo em seu proprio processo de aprendizado. O modelo preve a construcao de um ambiente em que haja uma maior interacao dos alunos tanto com colegas como com o professor, por meio de atividades e dinâmicas que estimulem esse tipo de comportamento. Neste contexto, a tecnologia pode ter um papel fundamental como facilitadora e em alguns caso viabilizadora dessas caracteristicas de interacao. Por exemplo a caneta eletronica, presente em dispositivos moveis como o Tablet PC, possibilita o registro natural do processo de desenvolvimento do pensamento e raciocinio, com a vantagem de permitir o uso conjunto de ferramentas que possibilitem um rapido e facil arquivamento, distribuicao, analise e comparacao do material por ela registrado. Nesse contexto, essa dissertacao apresenta uma proposta de desenvolvimento de uma ferramenta educacional, baseada no uso de dispositivos moveis com caneta eletronica, com o intuito de permitir a construcao de um ambiente educacional colaborativo, fundamentado no modelo do aprendizado ativo. Foi elaborado e implementado um prototipo da ferramenta, validado por experimentos realizados com o para medir a interacao dos alunos e do professor, alem da integracao do material dos alunos em sala de aula e sua posterior analise, organizacao e exibicao feitas pelo professor. Alem disso, foi possivel validar a interface proposta, as necessidades e caracteristicas especiais do uso da caneta eletronica em dispositivos moveis, no caso o Tablet PC. Os resultados obtidos permitiram identificar os beneficios e vantagens que a aplicacao de ferramentas interativas podem ter em sala de aula, como o aumento da participacao e interesse dos alunos e a capacidade do professor poder, em tempo real, ter o retorno de cada um dos alunos sobre o conteudo e conceitos apresentados durante a aula Abstract

Web Accessibility Metrics: Effects of Different Computational Approaches

Assessing and monitoring the accessibility of web pages are important challenges for ensuring universal accessibility of the web. In this paper, we analyse the quantitative results of the evaluation of web pages using four different metrics with different approaches to the aggregation of results from accessibility audits. The web pages evaluated are from three different Virtual Learning Environments (VLEs). The impact of the different aggregation approaches on the ranges of the values of the resulting metrics and on the ranking of web pages are discussed. We observe that the different approaches may provide different outcomes for comparison purposes, and argue that further investigations on the use of user data to improve the measurement of accessibility should be conducted.

InkBlog: A Pen-Based Blog Tool for e-Learning Environments

Weblogs are communication and collaborative tools disposed in Web that aims to publish texts and sharing opinions, typically displaying the post in reverse chronological order, and allowing visitors to leave comments. Since devices equipped with pen are becoming common, such as tablets, and have enough computational power to render Web pages, users can access blog tools through pen-based devices, writing new posts and read and comment published posts. But tablets have a different input style and the user need to type the post instead of handwriting it, decreasing the usability and make boring the writing task in these devices. Pen-based computing refers to a computer user-interface using a pen, rather than devices such as a keyboard or a mouse, and is a promise research area to enhance Education, but it is need to properly consider the pen. We purpose the InkBlog, a blog tool that receive input data from pen so that the user can handwriting her posts. In this work we present the InkBlog architecture and the main component, the InkEditor for Web pages. Using InkBlog the user can write equations or sketches faster than using a mouse or a keyboard, getting the best of the pen-based devices.