An empirical approach for evaluating the usability of model-driven tools

MDD tools are very useful to draw conceptual models and to automate code generation. Even though this would bring many benefits, wide adoption of MDD tools is not yet a reality. Various research activities are being undertaken to find why and to provide the required solutions. However, insufficient research has been done on a key factor for the acceptance of MDD tools: usability. With the help of end-users, this paper presents a framework to evaluate the usability of MDD tools. The framework will be used as a basis for a family of experiments to get clear insights into the barriers to usability that prevent MDD tools from being widely adopted in industry. To illustrate the applicability of our framework, we instantiated it for performing a usability evaluation of a tool named INTEGRANOVA. Furthermore, we compared the outcome of the study with another usability evaluation technique based on ergonomic criteria.This work has been developed with the support of the Intra European Marie Curie Fellowship Grant 50911302 PIEF-2010, MICINN (TIN2008-00555, PROS-Req TIN2010-19130-C02-02), GVA (ORCA PROMETEO/2009/015), and co-financed with ERDF. We also acknowledge the support of the ITEA2 Call 3 UsiXML (20080026) and financed by the MITYC under the project TSI-020400-2011-20. Our thanks also to Ignacio Romeu for the video data gathering setup.Condori-Fernandez, N.; Panach Navarrete, JI.; Baars, AI.; Vos, TE.; Pastor López, O. (2013). An empirical approach for evaluating the usability of model-driven tools. Science of Computer Programming. 78(11):2245-2258. https://doi.org/10.1016/j.scico.2012.07.017S22452258781

KERANGKA KERJA KOMPREHENSIF PENGUKURAN KEBERGUNAAN SITUS WEB UNTUK MENDUKUNG PENGUJIAN

Kebergunaan (usability) adalah salah satu faktor utama yang menentukan kualitas situs web (website). Banyak ahli yang telah membangun berbagai macam kerangka kerja (framework) untuk mengukur tingkat kebergunaan sebuah situs web. Namun hingga saat ini belum ada standar dan kakas bantu ditetapkan sebagai media pengukuran kebergunaan yang paling tepat dan akurat. Berdasarkan kelebihan dan kelemahan yang sudah dikaji pada penelitian sebelumnya, maka penelitian ini membangun kerangka kerja baru untuk pengukuran kebergunaan situs web. Kerangka kerja ini dibangun secara komprehensif dengan merumuskan konsep menggunakan koefisien indikator kebergunaan, kriteria kebergunaan, dan nilai relevansi untuk setiap kategori situs web. Pemetaan kriteria berdasarkan setap kategori situs web dilakukan lebih terperinci dengan pemberian nilai koefisien yang lebih konsisten. Kerangka kerja ini menghasilkan statistik nilai setiap kriteria dalam bentuk pemeringkatan berdasarkan prioritas nilai dari yang tertinggi hingga terendah sehingga dapat dijadikan sebagai acuan untuk melakukan pengujian situs web. Oleh sebab itu, peneliti berharap agar kerangka kerja ini dapat memberikan kontribusi untuk melakukan analisis pengujian situs web dengan hasil yang lebih terperinci dibanding kerangka kerja pada penelitian sebelumnya. Kata Kunci: Kebergunaan, situs web, kerangka kerja, pengujian, indikator, aspek, kriteria, koefisie

Usefulness model for the redesign of Graduate’s Student Management Information System

Postgraduate Student Management Information System (PSMI) is developed for managing the academic matters of postgraduate students, such as registration, appointment of supervisor, proposal defence, appointment of examiners and managing oral defence examination. The system which is known as SMASH was developed in the Faculty of Information Science and Technology, Universiti Kebangsaan Malaysia to facilitate the task of the Graduate Management Unit. However, SMASH is rarely used due to usability problems. Among the problems are, the administrative staffs are not aware of the graduate programs applications which are made through SMASH. There is a lack of functionality especially on the menu and the design of the interface. SMASH provides functionality that is limited to only download the application form. This paper discusses the usefulness model development that can be used as a guideline to improve the system. The usefulness model is developed by adapting IS0 9241 and ISO 9126 usability standards. This study employs User-Centered Design method which involves students and faculty administrative staffs. This study starts by identifying the usability problems through Heuristic Evaluation and analysing the user requirements through the system analysis and interview. The preliminary study discovers that there is a need for improvement in the interface design and the functionality of the system to meet user requirements. The user requirement analysis and the proposed improvement serves as the basis in redesigning the system prototype. The usefulness model is then verified by 30 respondents through survey

An empirical comparative evaluation of gestUI to include gesture-based interaction in user interfaces

[EN] Currently there are tools that support the customisation of users' gestures. In general, the inclusion of new gestures implies writing new lines of code that strongly depend on the target platform where the system is run. In order to avoid this platform dependency, gestUI was proposed as a model-driven method that permits (i) the definition of custom touch-based gestures, and (ii) the inclusion of the gesture-based interaction in existing user interfaces on desktop computing platforms. The objective of this work is to compare gestUI (a MDD method to deal with gestures) versus a code-centric method to include gesture-based interaction in user interfaces. In order to perform the comparison, we analyse usability through effectiveness, efficiency and satisfaction. Satisfaction can be measured using the subjects' perceived ease of use, perceived usefulness and intention to use. The experiment was carried out by 21 subjects, who are computer science M.Sc. and Ph.D. students. We use a crossover design, where each subject applied both methods to perform the experiment. Subjects performed tasks related to custom gesture definition and modification of the source code of the user interface to include gesture-based interaction. The data was collected using questionnaires and analysed using non-parametric statistical tests. The results show that gestUI is more efficient and effective. Moreover, results conclude that gestUI is perceived as easier to use than the code-centric method. According to these results, gestUI is a promising method to define custom gestures and to include gesture-based interaction in existing user interfaces of desktop-computing software systems. (C) 2018 Elsevier B.V. All rights reserved.This work has been supported by Department of Computer Science of the Universidad de Cuenca and SENESCYT of Ecuador, and received financial support from the Generalitat Valenciana under "Project IDEO (PROMETEOII/2014/039)" and the Spanish Ministry of Science and Innovation through the "DataMe Project (TIN2016-80811-P)".Parra-González, LO.; España Cubillo, S.; Panach Navarrete, JI.; Pastor López, O. (2019). An empirical comparative evaluation of gestUI to include gesture-based interaction in user interfaces. Science of Computer Programming. 172:232-263. https://doi.org/10.1016/j.scico.2018.12.001S23226317

Usability evaluation of variability modeling by means of Common Variability Language

Common Variability Language (CVL) is a recent proposal for OMG's upcoming Variability Modeling standard. CVL models variability in terms of Model Fragments. Usability is a widely-recognized quality criterion essential to warranty the successful use of tools that put these ideas in practice. Facing the need of evaluating the usability of CVL modeling tools, this paper presents a Usability Evaluation of CVL applied to a Modeling Tool for firmware code of Induction Hobs. This evaluation addresses the configuration, scoping and visualization facets. The evaluation involved the end users of the tool whom are engineers of our Induction Hob industrial partner. Effectiveness and efficiency results indicate that model configuration in terms of model fragment substitutions is intuitive enough but both scoping and visualization require improved tool support. Results also enabled us to identify a list of usability problems which may contribute to alleviate scoping and visualization issues in CVL.Echeverria, J.; Font, J.; Pastor López, O.; Cetina Englada, C. (2015). Usability evaluation of variability modeling by means of Common Variability Language. Complex Systems Informatics and Modeling Quarterly. (5):61-81. doi:10.7250/csimq.2015-5.05S6181

A Generic method for assembling software product line components

Software product lines (SPL) facilitate the industrialization of software development. The main goal is to create a set of reusable software components for the rapid production of a software systems family. Many authors propose different approaches to implement and assemble the reusable components of an SPL. However, the construction and assembly of these components continue to be a complex and time-consuming process. This thesis analyzes the advantages and disadvantages of the current approaches to implement and assemble the reusable components of an SPL. Taking advantage of these elements and with the goal of developing a generic method (which can be applied to several software components developed in different software languages), we develop Fragment-oriented programming (FragOP), a framework to design, implement and reuse SPL domain components. FragOP is based on: (i) domain components, (ii) domain files, (iii) fragmentation points, (iv) fragments, (v) customization points, and (vi) customization files. FragOP was implemented in an open-source tool called VariaMos, and we also carried out three evaluations: (i) we created a clothing stores SPL, derived five different products, and discussed the results. (ii) We developed a discussion about the comparison between FragOP and other approaches. And (iii) we designed and executed a usability test of VariaMos to support the FragOP approach. The results show preliminary evidence that the use of FragOP reduces the manual intervention when assembling SPL domain components and it can be used as a generic method for assembling assets and SPL components developed in different software languages.Las líneas de productos de software (LPS) promueven la industrialización del desarrollo de software mediante la definición y ensamblaje de componentes reutilizables de software. Actualmente existen diferentes propuestas para implementar y ensamblar estos componentes. Sin embargo, su construcción y ensamblaje continúa siendo un proceso complejo y que requiere mucho tiempo. Esta tesis analiza las ventajas y desventajas de las diferentes estrategias actuales para implementación y ensamblaje de componentes de LPS. Con base en esto y con el objetivo de desarrollar un método genérico (el cual se pueda aplicar a múltiples componentes de software desarrollados en diferentes lenguajes), esta tesis desarrolla la programación orientada a fragmentos (FragOP), la cual define un marco de trabajo para diseñar, implementar y reutilizar componentes de dominio de LPS. FragOP se basa en: (i) componentes de dominio, (ii) archivos de dominio, (iii) puntos de fragmentación, (iv) fragmentos, (v) puntos de personalización, y (vi) archivos de personalización. Además, se realizó una implementación de FragOP en una herramienta llamada VariaMos, y se llevaron a cabo tres evaluaciones: (i) se creó una LPS de tiendas de ropa, se derivaron cinco productos y se discutieron los resultados. (ii) Se realizó una discusión acerca de la comparación de FragOP y otras propuestas actuales. Y (iii) se diseñó una prueba de usabilidad acerca del soporte de VariaMos para FragOP. Los resultados muestran evidencia preliminar de que el uso de FragOP reduce la intervención manual cuando se ensamblan componentes, y que FragOP puede usarse como un método genérico para el ensamblaje de componentes.Doctorad

Evaluación de la Usabilidad en Términos de Eficiencia, Eficacia y Satisfacción de la Herramienta INTEGRANOVA

Cada día la usabilidad es más importante en el desarrollo y uso de distintos tipos de productos software. En el caso de las herramientas de desarrollo de software dirigido por modelos (en inglés, Model-Driven Development, MDD), a pesar de los beneficios que aportan tales como la reducción de costos y de tiempo de desarrollo, existen estudios que determinan que éstas todavía no poseen una amplia aceptación debido a la falta de usabilidad de las herramientas de MDD. El objetivo de este trabajo es la evaluación de la usabilidad de la herramienta de MDD INTEGRANOVA con respecto a los atributos de eficacia, eficiencia y satisfacción global. En concreto, se realiza un estudio empírico para analizar la usabilidad del editor del modelo de objetos de INTEGRANOVA, desde el punto de vista del desarrollador de software orientado a objetos (OO) y considerando diferentes niveles de experiencia con herramientas de MDD. La evaluación que se lleva a cabo en esta investigación se realiza desde dos puntos de vista complementarios siguiendo las recomendaciones de la disciplina de la Interacción Persona-Ordenador (IPO): desde el punto de vista de la evaluación con expertos, mediante la técnica de evaluación heurística de INTEGRANOVA, que ha permitido identificar problemas y mejoras de usabilidad para la interfaz de esta herramienta, y desde el punto de vista de la evaluación con usuarios finales a través de la técnica de observación directa. En este último tipo de evaluación, este trabajo incorpora un aspecto normalmente ausente en la IPO, que es la realización de un estudio empírico mediante el diseño de un cuasi experimento para obtener evidencias empíricas sobre si los usuarios con experiencia en el uso de herramientas de MDD similares a INTEGRANOVA (pero no con INTEGRANOVA) realizan un conjunto de tareas de modelado de clases con diferente dificultad interaccionando con INTEGRANOVA con mayor eficacia, eficiencia y satisfacción global que los usuarios sin experiencia. Una vez realizada la observación directa con ocho sujetos expertos y ocho sujetos novatos, que llevan a cabo 18 tareas de modelado OO de dificultad fácil, media y difícil, y obtenido los valores de eficacia, eficiencia y satisfacción global, se establece un estudio estadístico donde se analizan los estadísticos descriptivos básicos y los diagramas de caja para las diferentes combinaciones de factores. Además, para la variable dependiente eficiencia, al disponer de datos suficientes, se ha planteado un test ANOVA para cada una de las dos medidas en las que se descompone dicha variable: eficiencia propiamente dicha (tiempo que un sujeto necesita para completar la tarea) y eficiencia relativa (porcentaje de completitud de la tarea realizada en relación con el tiempo empleado en dicha tarea), considerando los dos grupos de sujetos y los tres niveles de dificultad de las tareas. Los resultados permiten afirmar que existen diferencias estadísticamente significativas entre los expertos y novatos y la eficiencia relativa al realizar las tareas de modelado con diferentes niveles de complejidad, obteniendo mejores valores los expertos en completar las tareas difíciles, de dificultad media y fáciles que los novatos. Sin embargo, en el tiempo empleado para la realización de las diferentes tareas no se observa un efecto significativo del nivel de experiencia de los usuarios, aunque los expertos son mucho más rápidos en la ejecución de los distintos tipos de tareas. vi Además, los expertos realizan cerca del 95% de las tareas tanto fáciles como medias y del 45% de las tareas difíciles frente a un porcentaje similar para las tareas fáciles, del 70% para las tareas medias y 10% para las tareas difíciles realizadas por los novatos. Por último, los resultados de satisfacción obtenidos para los sujetos partícipes tanto novatos como expertos revelan cierta insatisfacción durante la realización de las tareas con la aplicación, que presenta un nivel de usabilidad marginal. Los resultados obtenidos indican diferencias apreciables entre sujetos expertos y novatos así como también en las dificultades de las tareas (fácil, media y difícil). Sin embargo, el estudio refleja una mayor diferencia entre la dificultad de las tareas que el efecto de ser experto o novato.The importance of usability as part of the development and use of all sorts of software products is growing every day. Some studies have suggested that, despite its benefits like the reduction of development costs and time, model-driven development (MDD) is not widely accepted because MDD tools are not usable. The aim of this paper is evaluate the usability of one MDD tool, namely INTEGRANOVA, with respect to the attributes of effectiveness, efficiency and overall satisfaction. In fact, we conduct an empirical study to analyse the usability of the INTEGRANOVA object model editor from the viewpoint object-oriented (OO) software developers with different levels of expertise with respect to MDD tools. Following human-computer interaction (HCI) guidelines, the evaluation carried out in this research takes into account two complementary viewpoints: expert evaluation using the heuristic evaluation technique to evaluate INTEGRANOVA and end user evaluation using the direct observation technique. By means of heuristic evaluation, we were able to identify usability problems and improvements for the tool interface. Through the application of direct observation, this research took up an issue that is not usually addressed within HCI. To be exact, we conducted an empirical study with a quasi-experimental design in order to gather empirical evidence about whether users experienced in the use of MDD tools similar to INTEGRANOVA (but not INTEGRANOVA) interact more effectively and efficiently with INTEGRANOVA to perform a set of class modelling tasks of varying difficulty and are generally more satisfied with the tool than inexperienced users. The direct observation technique was applied to eight expert subjects and eight novice subjects. These subjects carried out 18 easy, medium and hard OO modelling tasks. A statistical study was conducted on resulting values for effectiveness, efficiency and overall satisfaction, analysing the basic descriptive statistics and the box plots for the different combinations of factors. Additionally, as there were sufficient data for the efficiency dependent variable, an ANOVA was conducted for each of the two measures into which this variable is decomposed: efficiency (time that it takes a subject to complete the task) and relative efficiency (percentage of the task completed with respect to the time spent on the task), considering the two subject groups and the three task difficulty levels. The results suggest that there are statistically significant differences between experts and novices with respect to their relative efficiency in performing the modelling tasks of different complexity levels. Experts were better at doing the difficult, medium and easy tasks than novices. However, user experience level was not found to have a significant effect on the time taken to complete the different tasks, although experts are much faster in performing such tasks. Additionally, experts perform nearly 95% of easy and medium tasks and 45% of the difficult tasks, whereas novices complete a similar percentage of easy tasks, 70% of medium tasks and 10% of difficult tasks. viii Finally, the results with respect to the overall satisfaction of both the novice and expert participants reveal some dissatisfaction during task performance using the application, which is found to have a low usability level. The results suggest that there are appreciable differences between both experts and novice subjects and with regard to task difficulty (easy, medium and difficult). Then again, the study indicates that task difficulty has a bigger effect than expertise

Método para la evaluación de usabilidad de sitios web transaccionales basado en el proceso de inspección heurística

La usabilidad es considerada uno de los factores más importantes en el desarrollo de productos de software. Este atributo de calidad está referido al grado en que, usuarios específicos de un determinado aplicativo, pueden fácilmente hacer uso del software para lograr su propósito. Dada la importancia de este aspecto en el éxito de las aplicaciones informáticas, múltiples métodos de evaluación han surgido como instrumentos de medición que permiten determinar si la propuesta de diseño de la interfaz de un sistema de software es entendible, fácil de usar, atractiva y agradable al usuario. El método de evaluación heurística es uno de los métodos más utilizados en el área de Interacción Humano-Computador (HCI) para este propósito debido al bajo costo de su ejecución en comparación otras técnicas existentes. Sin embargo, a pesar de su amplio uso extensivo durante los últimos años, no existe un procedimiento formal para llevar a cabo este proceso de evaluación. Jakob Nielsen, el autor de esta técnica de inspección, ofrece únicamente lineamientos generales que, según la investigación realizada, tienden a ser interpretados de diferentes maneras por los especialistas. Por tal motivo, se ha desarrollado el presente proyecto de investigación que tiene como objetivo establecer un proceso sistemático, estructurado, organizado y formal para llevar a cabo evaluaciones heurísticas a productos de software. En base a un análisis exhaustivo realizado a aquellos estudios que reportan en la literatura el uso del método de evaluación heurística como parte del proceso de desarrollo de software, se ha formulado un nuevo método de evaluación basado en cinco fases: (1) planificación, (2) entrenamiento, (3) evaluación, (4) discusión y (5) reporte. Cada una de las fases propuestas que componen el protocolo de inspección contiene un conjunto de actividades bien definidas a ser realizadas por el equipo de evaluación como parte del proceso de inspección. Asimismo, se han establecido ciertos roles que deberán desempeñar los integrantes del equipo de inspectores para asegurar la calidad de los resultados y un apropiado desarrollo de la evaluación heurística. La nueva propuesta ha sido validada en dos escenarios académicos distintos (en Colombia, en una universidad pública, y en Perú, en dos universidades tanto en una pública como en una privada) demostrando en todos casos que es posible identificar más problemas de usabilidad altamente severos y críticos cuando un proceso estructurado de inspección es adoptado por los evaluadores. Otro aspecto favorable que muestran los resultados es que los evaluadores tienden a cometer menos errores de asociación (entre heurística que es incumplida y problemas de usabilidad identificados) y que la propuesta es percibida como fácil de usar y útil. Al validarse la nueva propuesta desarrollada por el autor de este estudio se consolida un nuevo conocimiento que aporta al bagaje cultural de la ciencia.Tesi

Comprehensibility of Variability in Model Fragments for Product Configuration

[EN] The ability to manage variability in software has become crucial to overcome the complexity and variety of systems. To this end, a comprehensible representation of variability is important. Nevertheless, in previous works, difficulties have been detected to understand variability in an industrial environment. Specifically, domain experts had difficulty understanding variability in model fragments to produce the software for their products. Hence, the aim of this paper is to further investigate these difficulties by conducting an experiment in which participants deal with variability in order to achieve their desired product configurations. Our results show new insights into product configuration which suggest next steps to improve general variability modeling approaches, and therefore promoting the adoption of these approaches in industry.This work has been partially supported by the Ministry of Economy and Competitiveness (MINECO), through the Spanish National R+D+i Plan and ERDF funds under The project Model-Driven Variability Extraction for Software Product Lines Adoption (TIN2015-64397-R).Echeverría-Ochoa, J.; Pérez, F.; Cetina Englada, C.; Pastor López, O. (2016). Comprehensibility of Variability in Model Fragments for Product Configuration. Springer. 476-490. https://doi.org/10.1007/978-3-319-39696-5_29S476490Berger, T., Nair, D., Rublack, R., Atlee, J.M., Czarnecki, K., Wąsowski, A.: Three cases of feature-based variability modeling in industry. 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