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The earliest design decisions often have a significant impact on software quality and are the most costly to revoke. One of the challenges in architecture design is to reduce the frequency of retrofit problems in software designs; not being able to improve the quality of a system cost effectively, a problem which frequently occurs during late stages. Software architecture assessment is essential in the design of a high quality system. However, assessing the effect of individual design decisions with respect to quality is often complicated by the fact that it is hard to identify exactly how particular qualities and quality factors are improved or impaired by design decisions. In this paper we present a framework that formalizes some of the relationships between software architecture and software quality; it compiles existing design knowledge (quality improving patterns) in a format suitable for architecture assessment. This framework may prevent the retrofit problem and can assist in reasoning about intra- and inter- quality tradeoffs. We illustrate our framework by creating an instance for it for the qualities usability, security and safety.

Usability is currently a key feature for developing quality systems. A system that satisfies all the functional requirements can be strongly rejected by end-users if it presents usability problems. End-users demand intuitive interfaces and an easy interaction in order to simplify their work. The first step in developing usable systems is to determine whether a system is or is not usable. To do this, there are several proposals for measuring the system usability. Most of these proposals are focused on the final system and require a large amount of resources to perform the evaluation (end-users, video cameras, questionnaires, etc.). Usability problems that are detected once the system has been developed involve a lot of reworking by the analyst since these changes can affect the analysis, design, and implementation phases. This paper proposes a method to minimize the resources needed for the evaluation and reworking of usability problems. We propose an early usability evaluation that is based on conceptual models. The analyst can measure the usability of attributes that depend on conceptual primitives. This evaluation can be automated taking as input the conceptual models that represent the system abstractly.

Thanks to Open Data initiatives the amount of data available on the Web is rapidly increasing. Unfortunately, most of these initiatives only publish raw tabular data, which makes its analysis and reuse very difficult. Linked Data principles allow for a more sophisticated approach by making explicit both the structure and semantics of the data. However, from the user experience viewpoint, published datasets continue to be monolithic files which are completely opaque or difficult to explore by making complex semantic queries. Our objective is to facilitate the user to grasp what kind of entities are in the dataset, how they are interrelated, which are their main properties and values, etc. Rhizomer is a data publishing tool whose interface provides a set of components borrowed from Information Architecture (IA) that facilitate getting an insight of the dataset at hand. Rhizomer automatically generates navigation menus and facets based on the kinds of things in the dataset and how they are described through metadata properties and values. This tool is currently being evaluated with end users that discover a whole new perspective of the Web of Data.

Usability is a software system quality attribute. Although software engineers originally considered usability to be related exclusively to the user interface, it was later found to affect the core functionality of software applications. As of then, proposals for addressing usability at different stages of the software development cycle were researched. The objective of this paper is to present three reusable solutions at detailed design and programming level in order to effectively implement the Abort Operation, Progress Feedback and Preferences usability functionalities in web applications. To do this, an inductive research method was applied. We developed three web applications including the above usability functionalities as case studies. We looked for commonalities across the implementations in order to induce a general solution. The elements common to all three developed applications include: application scenarios, functionalities, responsibilities, classes, methods, attributes and code snippets. The findings were specified as an implementation-oriented design pattern and as programming patterns in three languages. Additional case studies were conducted in order to validate the proposed solution. The independent developers used the patterns to implement different applications for each case study. As a result, we found that solutions specified as patterns can be reused to develop web applications.

On the surface, one might think that revealing the factors that impact on software product usability and the success of an entire project would be relatively simple; however, reported evidence from practitioners and scholars frequently shows the opposite. The aim of this study was to determine factors with a positive (negative) impact on delivering usability in a software product and the success (failure) of an entire project. This paper presents the results of our study, where 11 factors were identified and described, along with an outline of 11 goal-oriented rules incorporating the expertise and knowledge of project managers. The elaborated body of knowledge, positively evaluated by IT professionals, would seem to be a valuable asset during the risk analysis performed before the kick-off of a project as well as in understanding the notion of usability.

Background: The use of chatbots has increased considerably in recent years. These are used in different areas and by a wide variety of users. Due to this fact, it is essential to incorporate usability in their development. Aim: Our objective is to identify the state-of-the-art in chatbot usability and applied human–computer interaction techniques, to analyze how to evaluate chatbot usability. Method: We have conducted a systematic mapping study, by searching the main scientific databases. The search retrieved 170 references and 21 articles were retained as primary studies. Results: The works were categorized according to four criteria: usability techniques, usability characteristics, research methods and type of chatbots. Conclusions: Chatbot usability is still a very incipient field of research where the published studies are mainly surveys, usability tests, and rather informal experimental studies. Hence, it becomes necessary to perform more formal experiments to measure user experience, and exploit these results to provide usability-aware design guidelines.

Extracting the usability requirements are crucial during requirements review and requirements validation for different purposes. Usability requirements are hard to be determined until the real user has experienced the software. It is even more challenging when these usability requirements are documented in natural language, which has an inconsistent and unrestricted structure. Automated requirements extraction has been widely studied to facilitate the process of requirements checking. Nevertheless, the accuracy of requirements extraction method still can be improved. Thus, this paper has presented the usability keywords repository that followed the ISO 9126 and ISO 25010 usability category and has gone through the expert validation process. The usability requirement extraction method is moreover enhanced with extra procedures in conforming the usability requirement statement. First, each statement in the requirement document is checked if there is a keyword usability, whereby the keywords used must match with the usability keyword repository. In order to ensure that the selected statement is a usability requirement, the corresponding usability keyword position should be after the fixed auxiliary verbs. The performance of the improved usability requirements extraction method is then evaluated using precision, recall and accuracy.

In this paper we present and discuss the results of the evaluation of an Intelligent Computer Assisted Language Learning (ICALL) system that operates over the Web. In particular, we aimed at evaluating the system along three dimensions: a) the effect of the intelligent features of the system on the learning outcome of students, b) the system's ability to provide individualized support to students that leads to more effective use of the system and c) the general usability and friendliness of the ICALL. To achieve this, we conducted an empirical study, where we compared the intelligent system with a non-intelligent version of it. The results of the study revealed that the students of the Web-based ICALL had gained more knowledge of the domain and had been able to interact with the system more effectively as compared to the students that had used the non-intelligent version of the system. However, the students of the intelligent version of the system found it more difficult and they needed more time to get acquainted with the system in comparison to the students of the non-intelligent system.

More of power wheelchair users’ needs have to be met in the making of power wheelchairs. However, there has been no usability scale for the power wheelchair that is specifically focusing on the users’ needs. The purpose of this study was to test and validate a usability scale for power wheelchairs (USPW). The USPW has been developed through interviews with power wheelchair and consultations with a panel of experts. The USPW consists of four evaluation categories (safety, operation, efficiency, and satisfaction). In order to validate it, its usability and the Quebec User Evaluation of Satisfaction Assistive Technology (QUEST) were also administered to 50 power wheelchair users. The USPW was extracted 12 items from safety, 7 from operation, 5 from efficiency, and 14 from satisfaction, with a total of 38 items. The content validity met the criteria. The total internal consistency (Cronbach’s $\alpha$) of the USPW was 0.75. Users of power wheelchair demanded that the safety of moving on the slopes, the satisfaction of storage space for power wheelchairs, and the repair service process would be improved. The correlation between the USPW and the QUEST was significant ($r=0.342,p<0.05$). The USPW may be very useful to evaluate overall usability of power wheelchair including its safety, operability, efficiency, and satisfaction. The developed usability scale (USPW) may help wheelchair makers become aware of the problems of present power wheelchairs and the users’ needs, allowing them to make better ones.

This paper explores the design of computer-based systems that support the management of organisational knowledge. The information systems notions of databases and information architectures are extended to the search for a meaningful conceptual structure by which collective knowledge can be supported by existing information technologies. An "architecture" is presented where the key unit of analysis is human activity as proposed by the cultural–historical activity theory. This architecture has the richness of the activity theory philosophy and yet addresses the issues of practical implementation from both the technical and organisational perspectives. The paper articulates the architecture and also reports on a study where its effectiveness was evaluation by a target group. An implementation of the architecture is also introduced.

Business Intelligence Tools (BI Tools) can be an intelligent way for individuals to undertake data analysis and reporting for guiding decision-making processes. There are many different BI Tools available in the market today, as well as information to assist organisations in evaluating their effectiveness. This paper focusses on two commercially available BI Tools: Tableau and Microsoft Power BI. It aims to determine which BI Tool is better for data analysis and reporting from an end user’s point of view. This paper undertakes an evaluation of both tools and compares which is more suitable for students using interface (navigation), cost, presence in the market, and available training and help as the evaluative criteria. Results produced in this paper found that overall, Tableau was more highly ranked than Power BI based on the evaluative criteria for end users for data analysis and reporting at least among the samples of the study. Tableau ranked higher than Power BI with its presence in the market, and available training and help. Power BI was rated more highly on its interface and both BI Tools were ranked the same in terms of cost to end users. This research is exploratory and may assist in formulating future research on BI Tools for specific user groups.

The rapid development of mobile user interfaces for students’ websites and the constant utilization of such interfaces by students have witnessed a significant upsurge in growth. However, mobile service providers may lack valuable feedback on user satisfaction, particularly for Arabic users, because the sites are designed and implemented without students’ participation. This paper empirically investigates the user satisfaction of a mobile banner system for the University of Ha’il in Saudi Arabia. Users’ satisfaction was evaluated across six scales: overall reactions, screens, terminology and system information, learning, system capabilities, and technical manuals and online help. A quantitative research method was utilized, involving a questionnaire survey of 235 students. We found that female students have significant concerns about user satisfaction. The paper proposes theoretical and practical implications for future work.

Split Hopkinson pressure bar (SHPB) technique is the most important test method to characterize dynamic stress–strain relations of various materials at different strain rates, and this technique requires uniform deformation of specimen during the experiment. However, some studies in recent years have found obvious deformation localization within metal foam specimens in SHPB tests, which may significantly affect the reliability of the results. Usability of SHPB to characterize dynamic stress–strain relation of metal foam becomes doubtful. In this paper, based on experimental verification, we carried out numerical simulative SHPB tests to study the problem, in which the metal foam specimens were modeled to have 3D meso structures with properties of their matrix material. Numerical simulative SHPB tests of aluminum foam specimens with varying thickness at different strain rates were performed. Deformation distribution in each local region of the specimen was examined and a concept of “effective specimen” was presented. Appropriate specimen thickness and range of testing strain rate were suggested based on quantitative analysis. Finally, we recommended a method how to revise the nominal strain and strain rate measured by traditional SHPB method to acquire the reliable dynamic stress–strain relation.

The ability to efficiently and effectively reuse ontologies is commonly acknowledged to play a crucial role in the large scale dissemination of ontologies and ontology-driven technology, being thus a pre-requisite for the ongoing realization of the Semantic Web. In this article, we give an account of ontology reuse from a process point of view. We present a methodology that can be utilized to systematize and monitor ontology engineering processes in scenarios reusing available ontological knowledge in the context of a particular application. Notably, and by contrast to existing approaches in this field, our aim is to provide means to overcome the poor reusability of existing resources — rather than to solve the more general issue of building new, more reusable knowledge components. To do so we investigate the impact of the application context of an ontology — in terms of tasks this ontology has been created for and will be utilized in — has on the feasibility of a reuse-oriented ontology development strategy and provide guidelines that take these aspects into account. The applicability of the methodology is demonstrated through a case study performed in collaboration with an international eRecruitment solution provider.

Tubular continuum robots can follow complex curvilinear paths to reach restricted areas within the body. Using teleoperation, these robots can help minimize incisions and reduce trauma. However, drawbacks include the lack of haptic feedback and a limited view of the situs, often due to camera occlusion. This work presents novel auditory display to enhance interaction with such continuum robots to increase accuracy and path-following efficiency and reduce cognitive workload. We recreate a typical use case with a test environment that simulates a transnasal intervention through the sphenoidal sinus including a simulated continuum robot. Distance information is mapped to changes in a real-time audio synthesizer using sung voice to provide navigation cues. User studies with novice participants and clinicians were performed to evaluate the effects of auditory display on accuracy, task time, path following efficiency, subjective workload, and usability. When using auditory display, participants exhibit significant increase in accuracy, efficiency, and task time compared to visual-only display. Auditory display reduced subjective workload and raised usefulness and satisfaction ratings. The addition of auditory display for augmenting interaction with a teleoperated continuum robot has shown to benefit performance as well as usability. The method could benefit other scenarios in navigated surgery to increase accuracy and reduce workload.

As our everyday financial interactions become increasingly digital, the abundance of mobile banking applications, methods of electronic payment, and online financial services available to everyday users offer new ways of interacting with money. These digital tools have the potential to transform our understanding of how financial operations occur, as well as how we make sense of our own personal financial information. There is still limited research to guide the design of personal financial management (PFM) tools and how to better support our digital financial interactions. While existing studies provide much-needed conceptual guidance and elaboration of contextual factors, there are still few studies that derive lessons from engaging in a user-centered design process that includes the evaluation of digital prototypes and explore the interactional challenges in designing tools for the mobile context. In this chapter we present an exploratory study in which we take a user-centered approach to developing and evaluating a digital prototype mobile application for PFM. We present our design decisions, discuss the usability implications of those decisions, and suggest ways in which future tools could be enhanced.

User-Centered Design (UCD) focuses on deeply understanding the needs of users and ensuring these needs are met by tools and software. UCD methodology aims to make tools easier to use, reduce time spent in development and the need for user support, as well as make it easier to create and maintain documentation. The goal of UCD is to ultimately make a tool that meets user needs and is a pleasure to use. This workshop will give an overview of UCD and several examples of how UCD practices are already being used at several institutions. Attendees will leave with ideas of how to incorporate UCD into their tool development as well as general resources to get started.

The objective of this chapter is to clarify the role of usability processes and methods within the software life cycle. After discussing the concept of usability as quality factor and providing various definitions, including those in ISO standards, it presents the user-centered design methodology for designing usable systems and provides indications on how to include usability in the software life cycle.

Different approaches can be applied to assess the usability of a web application. Each one of them presents advantages and drawbacks, as well as cost-benefits trade-offs. This contribution contains a short review of the state-of-the-art in web usability assessment issues, by focusing on a new systemic approach, called "e-usability", designed to deal in a more integrated way with the human-computer interaction, so as to allow a more realistic assessment of web interfaces. The applied methodology is quick and doesn't need any artifact design or evaluation cost.

It is essential that web designers understand what users expect of web services, how they perceive service quality dimensions such as security, usability and information quality, and which ones they value the most. In this study, the users' service quality perceptions of two different web sites were investigated. Data were obtained from 1,900 users of web sites of a for-profit online bookstore and a not-for-profit national information center through the E-Qual Index that was administered online. Findings of the study indicate that users of both for-profit and not-for-profit web sites attach more importance to the "trust" and "quality of information" dimensions as web service quality indicators. Users' expectations should therefore be regularly measured to review the design and information structures of both for-profit and non-profit web sites.