Freddy Paz

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.

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.

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.

Developing an ATM Interface Using User-Centered Design Techniques

ATM interfaces nowadays present serious issues in usability and accessibility, frustrating users’ interaction and leading them to make operational mistakes. For this reason, we present the development of graphical interfaces for ATMs of BBVA Continental Bank, which follows a process of user-centered design. The priority was to identify the real needs of users based on the context, and to understand how they interact with the interfaces. In order to validate our proposal, we established a model and a functional prototype. Later, we evaluated this new design with a usability test. Based on the defects that were found, we applied changes to improve the interfaces. Finally, after an in-depth analysis, we concluded that the designed interfaces were suitable for implementation in the ATMs of BBVA Continental Bank, due to the process followed and the acceptance by users.

Applying a user-centered design methodology to develop usable interfaces for an Automated Teller Machine

Developing an interface for ATM systems is a complex process. Among the issues of this process, are designs without a focus on the final user, a non-defined process, and missed time in meetings with new stakeholders every time. Because of this, one of the leading banks in Peru, BBVA Continental, in the context of its digital transformation, requested new methods and tools for the design of its ATM interfaces. In this sense, we proposed a new methodology, which involves a set of activities and the use of two techniques of user-centered design: storyboarding and video prototyping. This new proposal was employed to implement new features of the system and for the improvement of the current workflow and navigation. In both cases, we obtained promising results for the financial entity: a better time-to-market and a better satisfaction of the stakeholders.

Usability Testing as a Complement of Heuristic Evaluation: A Case Study

The usability assessment of software systems is becoming more relevant, especially when it comes to web-based systems. A well-built and user-friendly website is capable of capturing a potential customer. There are different methods to evaluate usability, including heuristic evaluation and usability testing with users. In the present work, the critical functionalities of an airline’s website were evaluated, such as the purchase of tickets, flight reservations, among others. First, a heuristic evaluation was performed and then a usability test with users. The evaluations were developed in an academic context and the participants were postgraduate students of a university. The problems detected in the first evaluation served to define specific tasks in the usability test with users. In this way, the results of the evaluations were complemented.

Comparing the Effectiveness and Accuracy of New Usability Heuristics

Nielsen’s usability heuristics are the most recognized assessment tool to conduct heuristic evaluations. However, in a previous study we demonstrated these principles fail to cover all aspects of usability in the emerging categories of software products. The current generation of applications is embedded of special features that are not considered by the conventional principles. For this reason, we have developed a new set of usability heuristics that provide accurate results when are used to evaluate transactional Web applications. In this paper, we present a comparative study, in which the effectiveness of our new proposal and the Nielsen’s approach are contrasted. For this purpose, two groups of students were trained in a different set of principles. Subsequently, they were requested to conduct a heuristic evaluation using the approach that was assigned. Then, the results were compared. The analysis establishes that our new proposal covers more features, is more understandable and is perceived as easy to use. Although the promising results, some improvements and more experiments are required in other scenarios.

Application of the Communicability Evaluation Method to Evaluate the User Interface Design: A Case Study in Web Domain

According to the Semiotic Engineering, the human-computer interaction is a way of communication between designers and users. The Communicability Evaluation Method (CEM) is a technique to assess this communication and determine the degree in which the designers achieve to convey users their design intents through the system interface. Most case studies that are described in the literature are focused on the evaluation of desktop applications. In this study, we present the results of a communicability evaluation to a transactional Web application. The experimental case was run by three specialists in the field of HCI and involved the participation of four university students from two academic programs in Computing. These users had to perform some tasks that were developed based on the results of a previous work. After an analysis of the interactions, we concluded that the Website can be difficult to use by users with no experience in the use of this type of software. There are certain aspects of the interface design that should be improved.

An approach for effort estimation in incremental software development using cosmic function points

Context: The current trend for software construction consists in developing software through increments, which is recommended by recognized methodologies such as Rational Unified Process or Agile Methodologies. Although Cosmic Functional Size Measurement Method is one of the most known techniques to estimate effort and cost in software projects, there is little evidence that indicates how to adapt it to non-waterfall lifecycles, such as incremental ones. Goal: This paper presents an approach called Incremental CFP that allows estimating effort for each increment using Cosmic Function Points (CFP) and COCOMOs effort adjustment factor (EAF). Method: In order to validate this new approach, we employed data from two different projects in which undergraduate students had to work originally with IFPUG function points. Results: The results were considered as promising given that the difference between the estimated effort and the real effort was lower than 30% for the second increment. Conclusions: With a minimum difference between the estimated effort and the real effort, it was possible to establish that the proposed technique is acceptable and predictive. However, more study cases should be performed before generalizing its applicability for different contexts.