Effects of a vertical keyboard design on typing performance, user comfort and muscle tension

To circumvent the awkward pronated hand position inherent to conventional horizontal keyboards, a vertical, split keyboard was designed with flexible cushions supporting the wrists, allowing relaxed hand and arm postures. During eight twice-weekly 30-min training sessions, the performance and subjective comfort of nine experienced typists were tested. Typing speed and error percentage, and surface electromyographic activity of six forearm muscles and two postural muscles were recorded in separate sessions at the end of each week. Typing speed rapidly recovered to the preset rate of 300 keystrokes/min and error percentages were similar for the two keyboards. The vertical keyboard caused lower muscular activity in especially finger extensor muscles, did not increase postural muscle activity, and self-reported comfort was higher. Thus, the vertical keyboard was easily mastered, was experienced as comfortable, and caused less stress on muscles sensitive to repetitive strain injuries.     

Modeling user experience: A case study on a mobile device

User experience (UX) consists of all aspects of interactions between a user and a product. Recently, many studies have been conducted to define the UX concept, but few studies have attempted to quantify UX. This paper proposed quantification models that integrate major elements of UX into a single index. A variety of models were proposed and evaluated including compensatory (i.e. simple linear, polynomial and S-shaped value) and non-compensatory (i.e. conjunctive and disjunctive) models. A case study with a commercial tablet PC was conducted in which a total of 26 subjects participated in a laboratory environment. Each participant performed a pretest ensuring the ability to make ratio judgments and then evaluated predefined dimensions with the modified magnitude estimation procedure. A total of 22 hierarchical dimensions were evaluated such as overall UX, its elements (i.e. usability, affect and user value) and sub-elements. Both compensatory and non-compensatory models had high performance in terms of goodness of fit. The results of this study are expected to help product or service designers develop indices representing an overall UX value.Relevance to industryThis study proposed quantification models that aggregate elements of UX. Although the UX index has been controversial, the single value developed by the models can be expected to help decision-makers understand about products or services intuitively.     

Software performance engineering: a case study includingperformance comparison with design alternatives

Software performance engineering (SPE) provides an approach to constructing systems to meet performance objectives. The authors illustrate the application of SPE to an example with some real-time properties and demonstrate how to compare performance characteristics of design alternatives. They show how SPE can be integrated with design methods and demonstrate that performance requirements can be achieved without sacrificing other desirable design qualities such as understandability, maintainability, and reusability     

Civilian pepper spray for self defense: Understanding user perception and impact of design on user performance

Pepper spray is widely used in the US, and is marketed as an effective self-defense device. While pepper spray can be useful in deterring an attacker, many pepper spray owners do not have any experience using it. There is a dearth of published studies that focus on civilian pepper-spray use, not to mention first time pepper-spray users. A study to analyze pepper-spray designs with first-time users, to see how the design, specifically the safety mechanism, affects response time and overall performance would be helpful. The study was conducted in 2 parts – a survey to understand user perception, and a lab experiment using a 2 × 2 randomized block design with two designs of pepper sprays (side-slide safety and flip-top safety) and the two starting locations for the pepper spray (purse or pocket) as the manipulated factors. Results revealed a significant difference in response times between the flip-top pepper-spray and the side-slide pepper-spray. There was also a significant difference in response times between using the index or thumb as the trigger finger but no significant difference in response times when the pepper-spray for location (purse or pocket). Overall, participants rated the side-slide device as the most effective self-defense device.Relevance to industryBecause there is no other research in the area of first-time pepper-spray users, let alone civilian pepper-spray users, much can be learned about how well people use these devices in a real-world situation, and when there is a highly stressful situation how well does pepper-spray allow an individual to protect him or herself. This study starts the discussion on some of these topics.     

A laboratory study of user characteristics and decision-making performance in end-user computing

A laboratory study using a simulated business setting was conducted to examine relationships among user characteristics, DSS usage patterns, and decision-making performance. MBA-student subjects self-selected into one of two categories: (1) “end-user programmers” who chose to use the DSS modeling language to develop personalized decision models, or (2) “command level users” who used only “canned” models and query language retrievals. The results show that early development of personalized decision models was positively related to the end-user's previous computer experience. The findings also support the contention that end-user programming improves decision-making performance. End-user programmers consistently outperformed the command level users in terms of their firm's stock price, market share, and return on assets.     

A case study of user immersion-based systematic design for serious heritage games

Modern digital technologies support the preservation and transfer of cultural heritage information via devices and applications such as digital storage systems, electronic books and virtual museums. Advances in virtual and augmented reality, real-time computer graphics and computer games have made it possible to construct large virtual environments in which users may experience cultural heritage through a variety of interactions and immersions. Thus, an emerging problem is to implement an appropriate systematic design method for achieving various types of entertainment, learning and information transfer. This paper proposes two important design factors that impact on user immersion in serious heritage games: user interface space volume and subsystem sequence. The impact of the two factors on proposed systematic design methods was investigated through comparative studies by implementing a serious heritage game system on three different platforms.     

Maintenance-oriented design and development: a case study

Maintenance efforts are the most time and resource consuming of the entire software development process. The authors propose a different point of view that shifts the traditional perspective and thinks of the implementation stage as maintenance as well. They present a case study of the development of educational video games for children to determine the proposed method's benefits and drawbacks in this domain.     

A case study of user evaluation of information characteristics for systems improvement

This paper reports on a case study of user evaluation of information characteristics as a basis for the improvement of an information system. Branch-managers of a large bank were asked to evaluate the output of the system according to four information characteristics: accuracy, content, frequency, and recency. The findings of this study indicate that the users at the bank had a holistic perception of their information, and that content was a dominant characteristics which spilled over other characteristics. This case study casts doubts about the use of evaluations of users of information characteristics as the only basis for improving existing systems.     

Enhanced ergonomics approaches for product design: a user experience ecosystem perspective and case studies

This paper first discusses the major inefficiencies faced in current human factors and ergonomics (HFE) approaches: (1) delivering an optimal end-to-end user experience (UX) to users of a solution across its solution lifecycle stages; (2) strategically influencing the product business and technology capability roadmaps from a UX perspective and (3) proactively identifying new market opportunities and influencing the platform architecture capabilities on which the UX of end products relies. In response to these challenges, three case studies are presented to demonstrate how enhanced ergonomics design approaches have effectively addressed the challenges faced in current HFE approaches. Then, the enhanced ergonomics design approaches are conceptualised by a user-experience ecosystem (UXE) framework, from a UX ecosystem perspective. Finally, evidence supporting the UXE, the advantage and the formalised process for executing UXE and methodological considerations are discussed.

Practitioner Summary: This paper presents enhanced ergonomics approaches to product design via three case studies to effectively address current HFE challenges by leveraging a systematic end-to-end UX approach, UX roadmaps and emerging UX associated with prioritised user needs and usages. Thus, HFE professionals can be more strategic, creative and influential.     

The Webkit tangible user interface: a case study of iterative prototyping

Here we describe our 18-month iterative-design program to create Webkit, a tangible user interface (TUI) to help school children learn argumentation skills - an English National Curriculum requirement. The goal was to have Webkit disappear into the environment such that the teachers and students remained focused on the learning activity. However, the school children wouldn't be allowed to evaluate our prototypes unless we showed that the classroom time allocated to our research simultaneously helped teach the curriculum. To achieve this, we developed a form of user-centered design called curriculum-focused design. When we used CFD, the curriculum and student needs motivated not just the final technology but also our design process.     

Facilitating data exploration with query previews: a study of user performance and preference

Networked and local data exploration systems that use command languages, menus, or form fill-in interfaces rarely give users an indication of the distribution of data. This often leads users to waste time, posing queries that have zero-hit or mega-hit results. Query previews are a novel visual approach for browsing databases. Query previews supply users with data distribution information for selected attributes of the database, and give continuous feedback about the size of the result set as the query is being formed. Subsequent refinements might be necessary to narrow the search. As there is a risk that query previews are an additional step, leading to a more complex and slow search process, a within-subjects empirical study was ran with 12 subjects who used interfaces with and without query previews and with minimized network delays. Even with 12 subjects and minimized network delays statistically significant differences were found, showing that query previews could speed up performance 1.6 to 2.1 times and lead to higher user satisfaction.     

Brittleness in the design of cooperative problem-solving systems:the effects on user performance

One of the critical problems in the design and use of advanced decision-support systems is their potential “brittleness”. This brittleness can arise because of the inability of the designer to anticipate and design for all of the scenarios that could arise during the use of the system. The typical “safety valve” to deal with this problem is to keep a person “in the loop”, requiring that person to apply his/her expertise in making the final decision on what actions to take. This paper provides empirical data on how the role of the decision support system can have a major impact on the effectiveness of this design strategy. Using flight planning for commercial airlines as a testbed, three alternative designs for a graphical flight planning tool were evaluated, using 27 dispatchers and 30 pilots as subjects. The results show that the presentation of a suggestion or recommendation by the computer early in the person's own problem evaluation can have a significant impact on that person's decision processes, influencing situation assessment and the evaluation of alternative solutions     

The influence of design aesthetics in usability testing: Effects on user performance and perceived usability

This article examined the effects of product aesthetics on several outcome variables in usability tests. Employing a computer simulation of a mobile phone, 60 adolescents (14-17 yrs) were asked to complete a number of typical tasks of mobile phone users. Two functionally identical mobile phones were manipulated with regard to their visual appearance (highly appealing vs not appealing) to determine the influence of appearance on perceived usability, performance measures and perceived attractiveness. The results showed that participants using the highly appealing phone rated their appliance as being more usable than participants operating the unappealing model. Furthermore, the visual appearance of the phone had a positive effect on performance, leading to reduced task completion times for the attractive model. The study discusses the implications for the use of adolescents in ergonomic research.     

Toward the design of transitional interfaces: an exploratory study on a semi-immersive hybrid user interface

A task that can be decomposed into subtasks with different technological demands may be a challenge, since it requires multiple interactive environments as well as transitions between them. Some of these transitions may involve changes in hardware devices and interface paradigms at the same time. Some previous works have proposed various setups for hybrid user interfaces, but none of them focused on the design of transition interactions. Our work emphasizes the importance of interaction continuity as a guideline in the design and evaluation of transitional interfaces within a hybrid user interface (HUI). Finally, an exploratory study demonstrates how this design aspect is perceived by users during transitions in an HUI composed by three interactive environments.     

Some effects of menu characteristics and user personality on performance with menu-driven interfaces

User performance with menu-based systems was studied. Three experiments concerning the effects of menu structure, menu breadth, menu system depth, several support facilities and user personality characteristics on user performance, measured in terms of search time and accuracy, are reported. The main findings are that performance is affected by menu structure, the depth of the menu system, the presence of escape facilities, the structure of the alternatives within the menu, some methods of informative support and certain personality characteristics. Some expensive support facilities are found to have no effect. The results are discussed in relation to problems of menu interface design.     

A cross-setting study of user unlocking behaviour in a graphical authentication scheme: a case study on android Pattern Unlock

International Journal of Information Security - Pattern Unlock studies have shown that users’ patterns exhibit biases that could result in ease of compromise. These biases range from the...     

Information characteristics and their impact on system performance: framework and case study in distributed production control

The judicious use of information is critical to the effective design and operation of intelligent systems such as flexible factories. Three key attributes of information are sufficiency, efficiency, and timeliness. We examine the impact of these parameters on system effectiveness through analytic models and simulation studies.     

Expertise, domain-structure and expert system design: a case study in development control

Abstract: This paper outlines the approach taken and presents some early findings from a research project which aims to examine the potential of expert systems in British Development Control; it is a progress report more than an account of finished research. It follows the structure of the research project, dealing first with methodological issues, and then moving on to discuss the specific domain of application.