Automatically Discovering, Reporting and Reproducing Android Application Crashes

Mobile developers face unique challenges when detecting and reporting crashes in apps due to their prevailing GUI event-driven nature and additional sources of inputs (e.g., sensor readings). To support developers in these tasks, we introduce a novel, automated approach called CRASHSCOPE. This tool explores a given Android app using systematic input generation, according to several strategies informed by static and dynamic analyses, with the intrinsic goal of triggering crashes. When a crash is detected, CRASHSCOPE generates an augmented crash report containing screenshots, detailed crash reproduction steps, the captured exception stack trace, and a fully replayable script that automatically reproduces the crash on a target device(s). We evaluated CRASHSCOPE's effectiveness in discovering crashes as compared to five state-of-the-art Android input generation tools on 61 applications. The results demonstrate that CRASHSCOPE performs about as well as current tools for detecting crashes and provides more detailed fault information. Additionally, in a study analyzing eight real-world Android app crashes, we found that CRASHSCOPE's reports are easily readable and allow for reliable reproduction of crashes by presenting more explicit information than human written reports.Comment: 12 pages, in Proceedings of 9th IEEE International Conference on Software Testing, Verification and Validation (ICST'16), Chicago, IL, April 10-15, 2016, pp. 33-4

UsaGame – A new methodology to support user- centered design of touchscreen game applications

Dissertação para Obtenção do Grau de Mestre em Engenharia e Gestão IndustrialTouchscreen mobile devices growth resulted in an explosion of the mobile applications. Focusing on touch mobile game applications this study aims to fulfill a research gap, creating appropriate usability guidelines for these applications. Concerns about usability, touch technologies, mobile devices and game testing, provided the background needs for this study. Initial game application tests allowed for the creation and implementation of such proposed usability guidelines into a support checklist (UsaGame), designed to help applications developers. An evaluation test was performed with 20 users in order to assess the validity of the proposed guidelines. Results from the test of the two builds from the same game application allowed comparisons that led to the assessment of the importance of some of the guidelines implemented into the application. Results suggested a usability improvement on the game application implemented with the guidelines. Furthermore results allowed commenting on all proposed usability guidelines

Enhancing creativity and play through accessible projector-based interactive PC-control touch technology

Standard computer peripherals are often challenging to use for mobility impaired, and in particular controlling computer mouse movements efficiently and without risking strain injuries. Projected touch screen technology show promise in this respect. This paper presents a Projected Interactive PC-control pilot (PIP) solution for computer interaction. The paper focus on testing and improving the usability of the PIP solution through iterative user tests with mobility impaired children. It describes prototype improvements aimed at fulfilling the requirements of users with reduced motor skills, and discusses challenges and key findings from the extensive usability tests. Our results demonstrates that interactive touch based solutions may enable heavily impaired children to independently partake in creative activities and play, and points to the value of creating a touch based computer interaction solution tailored to the needs of this user group

Completely Automated Public Physical test to tell Computers and Humans Apart: A usability study on mobile devices

A very common approach adopted to fight the increasing sophistication and dangerousness of malware and hacking is to introduce more complex authentication mechanisms. This approach, however, introduces additional cognitive burdens for users and lowers the whole authentication mechanism acceptability to the point of making it unusable. On the contrary, what is really needed to fight the onslaught of automated attacks to users data and privacy is to first tell human and computers apart and then distinguish among humans to guarantee correct authentication. Such an approach is capable of completely thwarting any automated attempt to achieve unwarranted access while it allows keeping simple the mechanism dedicated to recognizing the legitimate user. This kind of approach is behind the concept of Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA), yet CAPTCHA leverages cognitive capabilities, thus the increasing sophistication of computers calls for more and more difficult cognitive tasks that make them either very long to solve or very prone to false negatives. We argue that this problem can be overcome by substituting the cognitive component of CAPTCHA with a different property that programs cannot mimic: the physical nature. In past work we have introduced the Completely Automated Public Physical test to tell Computer and Humans Apart (CAPPCHA) as a way to enhance the PIN authentication method for mobile devices and we have provided a proof of concept implementation. Similarly to CAPTCHA, this mechanism can also be used to prevent automated programs from abusing online services. However, to evaluate the real efficacy of the proposed scheme, an extended empirical assessment of CAPPCHA is required as well as a comparison of CAPPCHA performance with the existing state of the art. To this aim, in this paper we carry out an extensive experimental study on both the performance and the usability of CAPPCHA involving a high number of physical users, and we provide comparisons of CAPPCHA with existing flavors of CAPTCHA

Advantages of using user experience design concepts in the creation of e-learning courses

Trabalho de Projeto de Mestrado, Educação (Área de Especialidade em Educação e Tecnologias Digitais), Universidade de Lisboa, Instituto de Educação, 2021This work focuses on the advantages of the application of User Experience Design concepts in the creation of e-learning courses showing how Instructional Designers can benefit from its application to improve the learning experience by following some of the rules and conventions for good website design. It starts by covering the definition of the term User Experience Design providing background information about the authors who have popularised the term, explaining its association with Usability, going through the advantages of applying it to e-learning courses, and ending with a practical application of the concepts. The practical component of the work lays on the assessment of a course to identify the elements that can be improved following the User Experience Design concepts found in the literature review and the application of those same concepts to a makeover of the original course that then allows the comparison of the two versions. Several elements in the original version were identified as needing improvement: blank space, lack of visual elements, navigation, clickable items, placement of the logo, responsiveness to different screens, and aesthetics. The course makeover was built using the authoring software Articulate Storyline that allowed the development of a version that promotes a better experience to the learner by reallocating some items, enhancing fonts and buttons, making it adjustable to different screen types, and modernising its layout. This work tries to prove that Instructional Designers can certainly benefit from applying User Experience Design concepts to help them identify some issues that otherwise could not be easily detected by simply following Instructional Design models.Este trabalho debruça-se sobre as vantagens da aplicação dos conceitos de User Experience Design na criação de cursos e-learning demonstrando como os Designers Instrucionais podem beneficiar de sua aplicação para melhorar a experiência de aprendizagem, seguindo algumas das regras e convenções base para um bom desenho de websites. Começa por abordar a definição do termo User Experience Design fornecendo informação histórica sobre os autores que o popularizaram, explanando a sua associação ao termo Usabilidade, passando pelas vantagens da sua aplicação em cursos de e-learning e terminando com demonstração da aplicação prática dos conceitos. A componente prática do trabalho consistiu na avaliação de um curso existente online para identificar os diferentes elementos que poderiam ser melhorados seguindo os conceitos de User Experience Design encontrados na revisão de literatura e aplicando desses mesmos conceitos numa nova versão do curso, permitindo-se adicionalmente a comparação entre ambas as versões. Na versão original, identificaram-se os seguintes elementos com necessidade de melhoria do ponto de vista de experiência do utilizador: espaço em branco, falta de elementos visuais, navegação, itens clicáveis, posicionamento do logotipo, responsividade do conteúdo a diferentes ecrãs e estética geral. A reformulação do curso foi desenvolvida com o software de autoria Articulate Storyline que possibilitou o desenvolvimento de uma versão que promove uma melhor experiência de aprendizagem através da recolocação de alguns itens, aprimoramento da tipografia e botões, maior adaptabilidade do conteúdo a diferentes tamanhos de ecrã e modernização do layout. Este trabalho mostra como os designers instrucionais podem beneficiar da aplicação de conceitos associados ao User Experience Design, demonstrando em que medidas estes o podem ajudar a identificar alguns problemas que, de outra forma, não seriam facilmente detetados apenas seguindo modelos associados ao Design Instrucional

Braille text entry on smartwatches : an evaluation of methods for composing the Braille cell

Smartwatches are gaining popularity on market with a set of features comparable to smartphones in a wearable device. This novice technology brings new interaction paradigms and challenges for blind users, who have difficulties dealing with touchscreens. Among a variety of tasks that must be studied, text entry is analyzed, considering that current existing solutions may be unsatisfactory (as voice input) or even unfeasible (as working with tiny QWERTY keyboards) for a blind user. More specifically, this paper presents a study on possible solutions for composing a Braille cell on smart-watches. Five prototypes were developed and different feedback features were proposed. These are confronted with seven specialists on an evaluation study that results in a qualitative analysis of which strategies can be more useful for blind users in a Braille text entry.Postprin