José Antonio Pow-Sang

A systematic review of usability techniques in agile methodologies

In this paper, we present the results of a systematic review involving the use of usability techniques in software developments where agile methodologies were used. The search strategy identified 307 studies, where only 32 were finally selected for the review. We found that complementary techniques are the most frequent techniques used with agile methodologies. In addition, most studies performed usability evaluations only during the implementation phase, and these evaluations were mostly constructed as elaborations of case studies.

Usability Heuristics for Transactional Web Sites

One of the most recognized methods to evaluate usability in software applications is the heuristic evaluation. In this inspection method, Nielsens heuristics, are the most widely used evaluation instrument. However, there is evidence in the literature which establishes that these heuristics are not appropriate when they are used to measure the level of usability of new emerging categories of software applications. This paper presents a case study where this concept is verified for Transactional Web Sites. Therefore, given the present limitations, a new set of usability heuristics was proposed following a structured and systematic methodology. Finally, fifteen new usability heuristics were obtained as final product of this research. A validation phase allowed to contrast this new proposal with the Nielsens principles under a real context, where a heuristic evaluation was performed to a Transactional Web Site. The results established that the new set of usability heuristics, which is presented in this study, provides more accurate and promising results than the current proposal of Nielsen.

An Approach of a Technique for Effort Estimation of Iterations in Software Projects

The estimation of effort and cost is still one of the hardest tasks in software project management. At the moment, there are many techniques to accomplish this task, such as function points, use case points and COCOMO, but there is not much information available about how to use those techniques in non-waterfall software lifecycles such as iterative or spiral lifecycles projects. This paper shows the results obtained when applying a technique to estimate the effort of each construction iteration in software development projects that use iterative-incremental lifecycles. The results were obtained from software projects of a fourth-year course in Informatics. The technique proposes the use of Function Points and COCOMO II.

Heuristic Evaluation as a Complement to Usability Testing: A Case Study in Web Domain

Usability testing is one of the most used methods to define the level of usability of a software product. However, there is always uncertainty to determine the best method that complements user testing in a depth usability assessment. Nowadays, the concern of many software developers is to identify an appropriate methodology, whose evaluation methods could be capable of measuring all usability aspects of a user interface. For this reason, we conducted a heuristic evaluation as a preliminary step to the implementation of a usability test, in order to determine in which extent these methods complement each other, and establish the gaps which are covered by each of them. The heuristic evaluation was performed by five specialists in the field of Human-Computer Interaction, who identified a total of fifty-nine usability problems in a transactional web site. Subsequently, a usability test was conducted with the participation of eight postgraduate students of a masters program in Informatics Engineering. The results show that most of the usability problems which were detected during the usability testing, had already been identified by the heuristic evaluation. Nevertheless, there were significant differences in the importance that was given to each problem. Usability experts emphasized in aspects that were not relevant to end users.

An Approach to Determine Software Requirement Construction Sequences Based on Use Cases

The majority of software development projects utilize the use cases technique to define software requirements, which are necessary to determine not only the scope of the software itself, but also the sequence in which this software will be constructed. Currently, there are several proposals to define the construction sequence of software requirements, but most of these proposals lack of ease of use from the developerpsilas perspective. This paper presents an approach to determine software construction sequences based on use cases precedence diagrams, which offers some advantages from the developerpsilas point of view. In order to demonstrate the technique, we also present a controlled experiment performed by people who had at least two years of experience in software projects. The results of this experiment show that our proposed technique, unlike other ad hoc techniques used, enables a more precise definition of the construction sequence.

Current Trends in Usability Evaluation Methods: A Systematic Review

Since usability is considered as a critical success factor for any software application, several evaluation methods have been developed. Nowadays, it is possible to find many proposals in the literature that address to evaluate usability issues. However, there is still discussion about what usability evaluation method is the most widely accepted by the scientific community. In this research, a systematic review was performed to identify the evaluation methods that have been more employed over the last three years in order to assess the level of usability of a software application. From these results, it has been possible to establish clear evidence about the current trends in this field. A total of 274 usability studies have allowed to reach useful information for scholars in this area.

Experimental Case Study of New Usability Heuristics

A widely used method to measure the level of usability of software applications is the heuristic evaluation. In this method, specialists commonly use the Nielsen’s heuristics to assess the usability of a software product. However, these principles address to general aspects and become inappropriate when they are used to evaluate new categories of software applications. For this reason, we previously proposed a new set of usability heuristics in the Web transactional domain. In this paper, we present an empirical analysis of our new proposal. For this purpose, fifteen undergraduate students were asked to perform a heuristic evaluation in which the new set of heuristics were employed. A survey was taken in order to capture their perceptions about the heuristics in four dimensions: ease of use, usefulness, intention to use and completeness. The results showed that the new heuristics meet the expectations. In addition, this analysis was compared with the results of a similar study that was performed to the current proposal of Nielsen. The results from this study have allowed to reach promising results in this area.

Evaluation of Usability Heuristics for Transactional Web Sites: A Comparative Study

Nielsen’s usability heuristics are the most commonly used assessment tool to perform a heuristic evaluation. However, when they are employed to evaluate the usability of transactional Web sites, they fail to cover all aspects of usability that are currently present in this kind of software. For this reason, we have developed a new proposal that is capable of providing more accurate results in this context. Our approach includes fifteen usability heuristics for the design of usable graphical user interfaces. This paper presents a comparative study between the classical Nielsen’s proposal and the new set of heuristics for transactional Web sites. The experimental case study was conducted following the Method Adoption Model which establishes the analysis of three dimensions: perceived ease of use, perceived usefulness and intention to use. For this purpose, forty-six undergraduate students were asked to perform a heuristic evaluation, in which both proposals were employed. The results showed that the new heuristics are easier to use than the traditional approach. This study provides the validation of an effective tool that can be used easily to perform heuristic evaluations in the context of transactional Web applications.

Replacing a traditional lecture class with a jigsaw class to teach analysis class diagrams

Cooperative or collaborative learning methods generate more significant and lasting knowledge in students. That is why the Jigsaw technique has been utilized in courses related to object-oriented software development, as reinforcement for the lectures previously given on each subject. Although this technique was used, in previous experiences, to reinforce the theoretical concepts taught in class, it was defined as a future work to determine if sessions based only on cooperative learning methods can replace traditional lecture classes. This paper will present the design of a Jigsaw class to teach analysis class diagrams that replaced a traditional lecture class, and the results obtained in this experience. The paper will include the comparison of the results of the test that was taken after the Jigsaw class with the results of the test that it was taken after a traditional lecture class in a previous semester. The grades obtained by the students when it was applied a test after the Jigsaw class are better than the grades obtained by the students who participated in a traditional lecture class.

Usability Evaluation Methods for Software Development: A Systematic Mapping Review

Usability is currently one of the most important aspects of software quality. Developers are aware that if a software product does not meet users expectations regarding usability, the entire project might fail. For this reason, several usability evaluation methods have emerged and nowadays are employed from early phases of the software development process. However, the literature reports a wide range of techniques for this purpose. In this way, the choice of a suitable method for a particular scenario has become a difficult decision. Through a systematic mapping review about the use of usability evaluation methods in software development contexts, we have identified the most commonly used techniques. A total of 228 case studies were selected for this review. We found that (1) Questionnaire, (2) User Testing and (3) Heuristic Evaluation were the most frequent. This study is intended to be a guide for scholars in this area.