Facets of prior experience and the effectiveness of inclusive design

Research in inclusive design has shown the importance of prior experience for the usability of interactive products. Prior experience, however, is an ill-defined and inconsistently used construct. A number of different definitions and operationalisations of experience exist, but the differing power of these operationalisations to predict the usability of products for older users has rarely been investigated systematically. This study seeks to fill that gap. It is argued that the construct of experience has at least three components. It is proposed that two of these components, exposure and competence, are directly relevant for the current discussion about prior experience in inclusive design and that they can predict to different degrees the usability of a product for older users. In an empirical study, these facets of expertise are each operationalised on three levels of specificity and their impact on usability is assessed. The results show that measures of competence predict usability variables more strongly than measures of exposure and that levels of medium and high specificity are the best predictors. The application of inclusive design principles to a redesigned version of a ticket vending machine—although not resulting in a difference of overall usability—changed the impact of prior experience on usability measures implying an enhanced inclusiveness of the redesign with regard to prior experience. The implications of these findings for the effectiveness of inclusive design for older users are discussed.     

The influence of user expertise and prototype fidelity in usability tests

An empirical study examined the impact of user expertise and prototype fidelity on the outcomes of a usability test. User expertise (expert vs. novice) and prototype fidelity (paper prototype, 3D mock-up, and fully operational appliance) were manipulated as independent variables in a 2 × 3 between-subjects design. Employing a floor scrubber as a model product, 48 users carried out several cleaning tasks. Usability problems identified by participants were recorded. Furthermore, performance, system management strategies and perceived usability were measured. The results showed that experts reported more usability problems than novices but these were considered to be less severe than those reported by novices. Reduced fidelity prototypes were generally suitable to predict product usability of the real appliance. The implications for the running of usability tests are specific to the fidelity of the prototype.     

Using task analysis to improve usability of fatigue modelling software

The design of any interactive computer system requires consideration of both humans and machines. Software usability is one aspect of human–computer interaction that can benefit from knowledge of the user and their tasks. One set of methods for determining whether an application enables users to achieve their predetermined goals effectively and efficiently is task analysis. In the present study, a task analysis was applied to the graphical user interface of fatigue modelling software used in industry. The task analysis procedure allowed areas of usability improvement to be identified and then addressed with alternate interface prototypes. The present method of task analysis illustrates a practical and efficient way for software designers to improve software usability, user effectiveness and satisfaction, by involving users in the design process.     

Exploring the benefits of the combination of a software architecture analysis and a usability evaluation of a mobile application

Designing easy to use mobile applications is a difficult task. In order to optimize the development of a usable mobile application, it is necessary to consider the mobile usage context for the design and the evaluation of the user-system interaction of a mobile application. In our research we designed a method that aligns the inspection method “Software ArchitecTure analysis of Usability Requirements realizatioN” SATURN and a mobile usability evaluation in the form of a user test. We propose to use mobile context factors and thus requirements as a common basis for both inspection and user test. After conducting both analysis and user test, the results described as usability problems are mapped and discussed. The mobile context factors identified define and describe the usage context of a mobile application. We exemplify and apply our approach in a case study. This allows us to show how our method can be used to identify more usability problems than with each method separately. Additionally, we could confirm the validity and identified the severity of usability problems found by both methods. Our work presents how a combination of both methods allows to address usability issues in a more holistic way. We argue that the increased quantity and quality of results can lead to a reduction of the number of iterations required in early stages of an iterative software development process.     

Scoping Analytical Usability Evaluation Methods: A Case Study

ABSTRACT

Analytical usability evaluation methods (UEMs) can complement empirical evaluation of systems: for example, they can often be used earlier in design and can provide accounts of why users might experience difficulties, as well as what those difficulties are. However, their properties and value are only partially understood. One way to improve our understanding is by detailed comparisons using a single interface or system as a target for evaluation, but we need to look deeper than simple problem counts: we need to consider what kinds of accounts each UEM offers, and why. Here, we report on a detailed comparison of eight analytical UEMs. These eight methods were applied to a robotic arm interface, and the findings were systematically compared against video data of the arm in use. The usability issues that were identified could be grouped into five categories: system design, user misconceptions, conceptual fit between user and system, physical issues, and contextual ones. Other possible categories such as user experience did not emerge in this particular study. With the exception of Heuristic Evaluation, which supported a range of insights, each analytical method was found to focus attention on just one or two categories of issues. Two of the three “home-grown” methods (Evaluating Multimodal Usability and Concept-based Analysis of Surface and Structural Misfits) were found to occupy particular niches in the space, whereas the third (Programmable User Modeling) did not. This approach has identified commonalities and contrasts between methods and provided accounts of why a particular method yielded the insights it did. Rather than considering measures such as problem count or thoroughness, this approach has yielded insights into the scope of each method.     

Scenario-focused development method for a pen-based user interface: model and applications

Pen-based user interface (PUI) has drawn significant interest, owing to its intuitiveness and convenience. While much of the research focuses on the technology, the usability of a PUI has been relatively low since human factors have not been considered sufficiently. Scenario-centric designs are ideal ways to improve usability. However, such designs possess some problems in practical use. To cope with these design issues, the concept of “interface scenarios” is proposed in to facilitate the interface design, and to help users understand the interaction process in such designs. The proposed scenario-focused development method for PUI is coupled with a practical application to show its effectiveness and usability.     

Affective impact of navigational and signaling aids to e-learning

College students had 30 min to study a 17-frame online lesson on distance learning that included navigational aids (for showing the learner’s location in the lesson), signaling aids (for highlighting the important content), both aids, or no aids. On a 30-item usability survey consisting of 8 usability scales, students who received navigational aids produced significantly higher mean ratings on each of the 8 usability scales—ease of use, satisfaction of use, awareness of lesson structure, awareness of lesson length, awareness of location, ease of navigation, lesson comprehension, and lesson learning—with effect sizes ranging from d = 0.50 to d = 1.35. Students who received signaling aids produced significantly higher ratings on 4 of the 8 usability scales—ease of use, satisfaction of use, lesson comprehension, and lesson learning with effect sizes ranging from d = 0.39 to d = 2.15. Results help to clarify the mechanism underlying previous findings showing that students learned more from e-lessons that contained navigational aids. In the present study, there was a significant positive correlation between usability rating and recall test score for 5 of the 8 usability scales (particularly for ease of use), indicating partial support for the prediction that learners’ satisfaction with an e-learning system is related to their learning outcome. Results support the predictions of the emotional design hypothesis and have implications for the design of e-learning interfaces.     

A usability evaluation of medical software at an expert conference setting

Introduction

A usability test was employed to evaluate two medical software applications at an expert conference setting. One software application is a medical diagnostic tool (electrocardiogram [ECG] viewer) and the other is a medical research tool (electrode misplacement simulator [EMS]). These novel applications have yet to be adopted by the healthcare domain, thus, (1) we wanted to determine the potential user acceptance of these applications and (2) we wanted to determine the feasibility of evaluating medical diagnostic and medical research software at a conference setting as opposed to the conventional laboratory setting.

Methods

The medical diagnostic tool (ECG viewer) was evaluated using seven delegates and the medical research tool (EMS) was evaluated using 17 delegates that were recruited at the 2010 International Conference on Computing in Cardiology. Each delegate/participant was required to use the software and undertake a set of predefined tasks during the session breaks at the conference. User interactions with the software were recorded using screen-recording software. The ‘think-aloud’ protocol was also used to elicit verbal feedback from the participants whilst they attempted the pre-defined tasks. Before and after each session, participants completed a pre-test and a post-test questionnaire respectively.

Results

The average duration of a usability session at the conference was 34.69 min (SD = 10.28). However, taking into account that 10 min was dedicated to the pre-test and post-test questionnaires, the average time dedication to user interaction of the medical software was 24.69 min (SD = 10.28). Given we have shown that usability data can be collected at conferences, this paper details the advantages of conference-based usability studies over the laboratory-based approach. For example, given delegates gather at one geographical location, a conference-based usability evaluation facilitates recruitment of a convenient sample of international subject experts. This would otherwise be very expensive to arrange. A conference-based approach also allows for data to be collected over a few days as opposed to months by avoiding administration duties normally involved in laboratory based approach, e.g. mailing invitation letters as part of a recruitment campaign.Following analysis of the user video recordings, 41 (previously unknown) use errors were identified in the advanced ECG viewer and 29 were identified in the EMS application. All use errors were given a consensus severity rating from two independent usability experts. Out of a rating scale of 4 (where 1 = cosmetic and 4 = critical), the average severity rating for the ECG viewer was 2.24 (SD = 1.09) and the average severity rating for the EMS application was 2.34 (SD = 0.97). We were also able to extract task completion rates and times from the video recordings to determine the effectiveness of the software applications. For example, six out of seven tasks were completed by all participants when using both applications. This statistic alone suggests both applications already have a high degree of usability. As well as extracting data from the video recordings, we were also able to extract data from the questionnaires. Using a semantic differential scale (where 1 = poor and 5 = excellent), delegates highly rated the ‘responsiveness’, ‘usefulness’, ‘learnability’ and the ‘look and feel’ of both applications.

Conclusion

This study has shown the potential user acceptance and user-friendliness of the novel EMS and the ECG viewer applications within the healthcare domain. It has also shown that both medical diagnostic software and medical research software can be evaluated for their usability at an expert conference setting. The primary advantage of a conference-based usability evaluation over a laboratory-based evaluation is the high concentration of experts at one location, which is convenient, less time consuming and less expensive.     

To twist or poke? A method for identifying usability issues with the rotary controller and touch screen for control of in-vehicle information systems

In-vehicle information systems (IVIS) can be controlled by the user via direct or indirect input devices. In order to develop the next generation of usable IVIS, designers need to be able to evaluate and understand the usability issues associated with these two input types. The aim of this study was to investigate the effectiveness of a set of empirical usability evaluation methods for identifying important usability issues and distinguishing between the IVIS input devices. A number of usability issues were identified and their causal factors have been explored. These were related to the input type, the structure of the menu/tasks and hardware issues. In particular, the translation between inputs and on-screen actions and a lack of visual feedback for menu navigation resulted in lower levels of usability for the indirect device. This information will be useful in informing the design of new IVIS, with improved usability.

Statement of Relevance: This paper examines the use of empirical methods for distinguishing between direct and indirect IVIS input devices and identifying usability issues. Results have shown that the characteristics of indirect input devices produce more serious usability issues, compared with direct devices and can have a negative effect on the driver–vehicle interaction.     

Usability Principles for Augmented Reality Applications in a Smartphone Environment

Through the rapid spread of smartphones, users have access to many types of applications similar to those on desktop computer systems. Smartphone applications using augmented reality (AR) technology make use of users' location information. As AR applications will require new evaluation methods, improved usability and user convenience should be developed. The purpose of the current study is to develop usability principles for the development and evaluation of smartphone applications using AR technology. We develop usability principles for smartphone AR applications by analyzing existing research about heuristic evaluation methods, design principles for AR systems, guidelines for handheld mobile device interfaces, and usability principles for the tangible user interface. We conducted a heuristic evaluation for three popularly used smartphone AR applications to identify usability problems. We suggested new design guidelines to solve the identified problems. Then, we developed an improved AR application prototype of an Android-based smartphone, which later was conducted a usability testing to validate the effects of usability principles.     

An investigation on Ribbon interface design guidelines for people with less computer literacy

In the recent years, there is an intense competition between software development companies to design better interfaces. In this marketing rat race, Ribbon interface came to make software user interface easier. After the introduction of Ribbon by Microsoft, it was widely used by various software development companies. Ribbon is a replacement for menus and toolbars and it tends to organize tools in tabs based on their similarities. Although Ribbon interface has many advantages, previous researches have shown that there are serious usability issues that hinder usage of Ribbon interfaces for users with less computer literacy. In order to solve Ribbon interfaces usability issues, this study tried to introduce Ribbon interface design guidelines by focusing on the issues related to users with less computer literacy. In this study two separate sets of moderated (in-person) usability testing were used. The first set evaluated the usability issues of an experimental Ribbon interface software in terms of both visual and cognitive issues. The second set was used to evaluate the Ribbon interface prototype that was designed based on the discovered usability issues in the first usability test. In order to ensure the validity of the data, the researchers tried to triangulate the data collection process by collecting data from different sources, namely, quantitative measurement of participants' performance, direct observation, and interview. Based on the comparison of the usability tests results which points out the factors that have led to participants' performance improvement in the prototype version, a number of guidelines are extracted for Ribbon interfaces. These guidelines are applicable to Microsoft Office, Microsoft SharePoint and most of the software that can be developed with Ribbon interface. Putting these guidelines into action, self-learning would be promoted and learning issues of users with less computer literacy would be decreased.     

A design-and-play approach to accessible user interface development in Ambient Intelligence environments

User interface development in Ambient Intelligence (AmI) environments is anticipated to be a particularly complex and programming intensive endeavor. Additionally, AmI environments should ensure accessibility and usability of interactive technologies by users with different characteristics and requirements in a mainstream fashion. Therefore, appropriate user interface development methods and tools are required, capable of both reducing development efforts and ‘injecting’ accessibility issues into AmI applications from the early design stages. This paper introduces two tools, named AmIDesigner and AmIPlayer, which have been specifically developed to address the above challenges through automatic generation of accessible Graphical User Interfaces in AmI environments. The combination of these two tools offers a simple and rapid design-and-play approach, and the running user interfaces produced integrate non-visual feedback and a scanning mechanism to support accessibility. AmIDesigner and AmIPlayer have been evaluated to assess their usability by designers, and have been put to practice in the redevelopment of a light control application in a smart environment as a case study demonstrating the viability of the design-and-play approach. The results confirm the usefulness and usability of the tools themselves. Overall, the proposed approach has the potential to contribute significantly to the development, up-take and user acceptance of AmI technologies in the home environment.     

The usability and ergonomics of axes

This study evaluated the ergonomics and usability of axes. Several methods were used, namely measurement of impact velocity, the determination of kinetic energy, splitting performance tests, durability tests of blades and handles, and user trials. The mean velocity used in the striking was 9.6 m/s (8.9-10.3 m/s, SD 1.5). In the durability tests, the blades withstood the test reasonably well. In the bending tests, there were differences in the durability of the handles, which related to their material. A wide variation in the durability of the axe handles was also observed. User trials were conducted to evaluate the various features of the axes.     

Online help for the general public: specific design issues and recommendations

This paper addresses the issue of how to design online help that will really prove effective, accessible, and usable for all categories of users in the coming Information Society and, most of all, that will actually be used by novice users. The paper demonstrates the intrinsic necessity of online help and the actual failure of approaches claiming that transparent user interfaces eliminate the need for online support chiefly on the grounds that they encourage exploration. Empirical results in the literature or stemming from analyses of data we collected are put forward in the discussion. Based on a brief survey of the relevant literature, the major specific design issues that designers of online help systems are confronted with are presented, existing design approaches that might contribute to solving these issues are discussed, and a realistic short-term approach for improving the accessibility, effectiveness, and usability of online help systems is recommended. Our recommendation is mainly based on the results of a recently performed experimental study. These results led us to advise, at least for the near future, the design of noncontextual help systems for improving the accessibility, effectiveness, and usability of online help, rather than the implementation of dynamic adaptation to the current users cognitive profile or the development of contextual help systems that generate the information content of help messages dynamically according to the users current intention and goal. We assume that it is possible, within the framework of universal design principles, to significantly enhance the effectiveness and usability of standard noncontextual help systems, mainly by making the most of the recent advances in research on multimodal interaction, especially on the integration of speech into input modalities.     

Chinese character entry for mobile phones: a longitudinal investigation

The increasing popularity of Short Message Services (SMS) in China highlights the need for effective and efficient methods for entering Chinese text on mobile phones. While stroke-based methods have potential advantages over pronunciation-based solutions, usability issues have limited the effectiveness of existing stroke-based methods. One significant usability challenge has been the ambiguous stroke-to-key mapping rules that are typically employed. We proposed a new solution that employs a combination of abstract symbols and example strokes to help users map strokes to keys more effectively. A longitudinal experiment was used to evaluate character entry performance using both objective and subjective measures for our new design as well as the existing solution. The results confirmed that a new design allows for improved performance as well as higher satisfaction levels as compared to the original design. Further, after approximately 1 h of experience with the stroke-based method, novices were able to enter Chinese text at speeds comparable to that observed with the pronunciation-based Pinyin method. Results showed that the new design provided users with a better understanding of the system throughout the study, beginning with their first exposure to the keypad. By utilizing a combination of abstract representations and concrete examples of the available strokes, the new design reduced the ambiguity that typically exists regarding stroke-to-key mappings. In this way, usability was improved without any changes to the underlying technologies. Our results demonstrate that stroke-based solutions for Chinese character entry can be effective alternatives for mobile phones, providing an effective alternative for the many individuals who can write Chinese but do not speak the Mandarin dialect that serves as the basis for Pinyin. The improved solution could also be used with a traditional numeric keypad to allow one-handed data entry for desktop or mobile computers.     

User interface based on natural interaction design for seniors

With world population ageing, how to help seniors to adapt to technology life is an important issue. Technology is becoming life rather than resistance, because many of the technology applications are often accompanied by a lot of information to process. This makes the user interface to become an important bridge between human computer interactions. Especially the inconvenience caused by human ageing, these related issues from the cognitive and operational of products are derived. This study proposes a study of user interface design based on natural interaction to increase seniors’ usage intention. In the proposed contents, the Kinect sensor is used to retrieve seniors’ in-depth information in movements, thus the user interface of system can be operated by the gesture intuitively. In the framework of the system, in the first all, the morphology is applied to identify the features of a hand from depth values obtained from the sensor. Gesture is used to recognize operating behavior of users to implement the interactive action, and collision detection is applied to confirm effectiveness of operation. On the other hand, through interpretive structural model (ISM), each design element of interactive interface can be decomposed and realized, and the solution for target and direction of design problem is also proposed. At the meanwhile, the concept of affordance is conducted to the development of interface for graphic users that proposed in this study, and the design achievement contains operation and usability of intuition can further be acquired. Finally, based on the proposed methodology, an intuitive user interface of digital devices is constructed by Java programming language that allows for verifying the feasibility of user interface for seniors. Besides, the proposed method can be widely used to develop the user interface for various products.     

Usability measurement in context

Abstract

Different approaches to the measurement of usability are reviewed and related to definitions of usability in international standards. It is concluded that reliable measures of overall usability can only be obtained by assessing the effectiveness, efficiency and satisfaction with which representative users carry out representative tasks in representative environments.This requires a detailed understanding of the context of use of a product. The ESPRIT MUSiC project has developed tools which can be used to measure usability in the laboratory and the field. An overview is given of the methods and tools for measuring user performance, cognitive workload, and user perceived quality.     

A comparison of usability evaluation methods for evaluating e-commerce websites

The importance of evaluating the usability of e-commerce websites is well recognised. User testing and heuristic evaluation methods are commonly used to evaluate the usability of such sites, but just how effective are these for identifying specific problems? This article describes an evaluation of these methods by comparing the number, severity and type of usability problems identified by each one. The cost of employing these methods is also considered. The findings highlight the number and severity level of 44 specific usability problem areas which were uniquely identified by either user testing or heuristic evaluation methods, common problems that were identified by both methods, and problems that were missed by each method. The results show that user testing uniquely identified major problems related to four specific areas and minor problems related to one area. Conversely, the heuristic evaluation uniquely identified minor problems in eight specific areas and major problems in three areas.     

基于PCTBTA任务模型的用户界面开发方法

为了适应普适计算环境中用户、设备、使用环境和开发平台的多样性,基于模型的方法被应用于用户界面开发过程中,试图在抽象层次上描述界面,通过模型转换,使其适用于不同的平台.然而,由于目前基于模型的用户界面开发方法（model-based user interface development,简称MBUID）中所采用任务模型的局限性,致使生成的界面难以满足动态环境下用户的可用性需求.提出一种基于任务模型的用户界面开发框架,旨在建模和生成有效、高效、令用户满意的用户界面.在可用性方面,为了准确描述普适计算环境中用户任务,提出一种基于感知控制理论的任务分析方法（perceptual-control-theory-based task analysis,简称PCTBTA）,将使用上下文信息引入到任务分析过程中,并且在较高的抽象层次上反映交互的内容,给可用性设计提供任务空间;在技术方面,为PCTBTA任务模型向界面模型的转换提供技术支持.最后,通过实例说明所提出方法的可行性,并通过与其他方法在可用性和性能方面的比较,表明该方法的有效性.     

BLUFADER: Blurred face detection & recognition for privacy-friendly continuous authentication

Authentication and de-authentication phases should occur at the beginning and end of secure user sessions, respectively. A secure session requires the user to pass the former, but the latter is often underestimated or ignored. Unattended or dangling sessions expose users to well-known Lunchtime Attacks. To mitigate this threat, researchers focused on automated de-authentication systems, either as a stand-alone mechanism or as a result of continuous authentication failures. Unfortunately, no single approach offers security, privacy, and usability. Face-recognition methods, for example, may be suitable for security and usability, but they violate user privacy by continuously recording their actions and surroundings.In this work, we propose BLUFADER, a novel continuous authentication system that takes advantage of blurred face detection and recognition to fast, secure, and transparent de-authenticate users, preserving their privacy. We obfuscate a webcam with a physical blur layer and use deep learning algorithms to perform face detection and recognition continuously. To evaluate BLUFADER’s practicality, we collected two datasets formed by 30 recruited subjects (users) and thousands of physically blurred celebrity photos. The de-authentication system was trained and evaluated using the former, while the latter was used to appraise the privacy and increase variance at training time. To guarantee the privacy-preserving effectiveness of the selected physical blurring filter, we show that state-of-the-art deblurring models are not able to revert our physical blur. Further, we demonstrate that our approach outperforms state-of-the-art methods in detecting blurred faces, achieving up to 95% accuracy. Moreover, BLUFADER effectively de-authenticates users up to 100% accuracy in under 3 seconds, while satisfying security, privacy, and usability requirements. Last, our continuous authentication face recognition module based on Siamese Neural Network preventively protect users from adversarial attacks, enhancing the overall system security.