Utilising psychophysical techniques to investigate the effects of age,typeface design,size and display polarity on glance legibility

Psychophysical research on text legibility has historically investigated factors such as size, colour and contrast, but there has been relatively little direct empirical evaluation of typographic design itself, particularly in the emerging context of glance reading. In the present study, participants performed a lexical decision task controlled by an adaptive staircase method. Two typefaces, a ‘humanist’ and ‘square grotesque’ style, were tested. Study I examined positive and negative polarities, while Study II examined two text sizes. Stimulus duration thresholds were sensitive to differences between typefaces, polarities and sizes. Typeface also interacted significantly with age, particularly for conditions with higher legibility thresholds. These results are consistent with previous research assessing the impact of the same typefaces on interface demand in a simulated driving environment. This simplified methodology of assessing legibility differences can be adapted to investigate a wide array of questions relevant to typographic and interface designs.

Practitioner Summary: A method is described for rapidly investigating relative legibility of different typographical features. Results indicate that during glance-like reading induced by the psychophysical technique and under the lighting conditions considered, humanist-style type is significantly more legible than a square grotesque style, and that black-on-white text is significantly more legible than white-on-black.     

Reading upper and lower case on Viewdata

The times taken to read aloud six passages of nonsense text presented in upper or lower case on an ITT Viewdata receiver were compared. Contrary to the usual finding with printed material, upper case text did not significantly retard reading.     

Cognitive ergonomics of a mail order filling company: part 1 - influence of colour, position and highlighting on recognition time

Filling mail order request forms requires the picker to determine if the items ordered on the form are in his/her bay, reading the bin address and picking the item. An order form was investigated to determine if ergonomics improvements would result in improved productivity and accuracy. Colour, position and highlighting cues were systematically varied in a computer-simulated version of the picking task. It was concluded that colour and position significantly influence the processing time, while highlighting had no effect on processing time. Expert pickers were slower, but more accurate than the novine pickers. Recommendations for improving the order forms were made and implemented, with very encouraging results.     

The effects of Chinese typeface design,stroke weight,and contrast polarity on glance based legibility

Modern interfaces increasingly rely on screens filled with digital text to display information to users. Previous research has shown that even relatively subtle differences in the design of the on-screen typeface can influence to-device glance time in a measurable and meaningful way (Reimer et al., 2014). Here we outline a methodology for rapidly and flexibly investigating the legibility of typefaces on digital screens in glance-like contexts, and apply this method to a comparison of 5 Simplified Chinese typefaces. We find that the legibility of the typefaces, measured as the minimum presentation time needed to read character strings accurately and respond to a yes/no lexical decision task, is sensitive to differences in the typeface’s design characteristics. The most legible typeface under study (“MT YingHei”) could be read 33.1% faster than the least legible typeface in this glance-induced context. A second study examined two different weights of the MT YingHei type family (medium and bold), as well as two contrast polarity (color) conditions to investigate how these variations impact legibility thresholds. Results indicate that bold weight text is easier to read in this enforced glance-like context, and that positive polarity text (black on white) is easier to read compared to white on black text under the lighting conditions considered. These results are discussed in terms of contextual factors that may mediate glance-reading behavior, as well as how type design interacts with the practical limitations of a moderate density pixel grid.     

The influence of laboratory set-up in usability tests: effects on user performance,subjective ratings and physiological measures

This article examines the influences of situational factors on user behaviour in usability tests. Sixty participants carried out two tasks on a computer-simulated prototype of a mobile phone. Employing a 3 × 2 mixed experimental design, laboratory set-up was varied as a between-subjects variable (presence of facilitator and two non-interactive observers, presence of facilitator or no person present) while task difficulty was manipulated as a within-subjects variable (low vs. high). Performance data, subjective measures and physiological parameters (e.g. heart rate variability) were taken. The results showed that the presence of non-interactive observers during a usability test led to a physiological stress response, decreased performance on some measures and affected the emotional state of test participants. The presence of a facilitator (i.e. a participating observer) also influenced the emotional state of the test participant. Practitioners involved in usability testing need to be aware of undue influences of observers, in particular, if the observers are non-interactive. The findings presented in this paper have implications for the practice of usability testing. They indicated a considerable influence of observers on test participants (physiology and emotions) and on the outcomes of usability tests (performance measures). This should be considered when selecting the set-up of a usability testing procedure.     

The effects of usability and web design attributes on user preference for e-commerce web sites

This study examines the relationships among perceived usability before actual use, task completion time, and preference, and the effects of design attributes on user preference for e-commerce web sites. Nine online bookstore web sites were used by ten participants. Results indicate: (1) pre-use usability and task completion time were correlated; (2) the relationship between pre-use usability and preference was greater than that of task completion time and preference; (3) design attribute assessments after actual use were highly intercorrelated; and (4) organizational structure and layout had a greater effect on user preference than aesthetic aspects, such as color and typography. These findings can be used to construct a conceptual framework for understanding user preferences and to develop design guidelines to yield more highly preferred e-commerce web sites. Also, the methodology in this study can be applied to other computerized-applications.     

Productivity, satisfaction, and interaction strategies of individuals with spinal cord injuries and traditional users interacting with speech recognition software

Speech recognition is an important technology that is becoming increasingly effective for dictation-oriented activities. While recognition accuracy has increased dramatically in recent years, recent studies confirm that traditional computer users are still faster using a keyboard and mouse and spend more time correcting errors than dictating. Further, as these users become more experienced they frequently adopt multimodal strategies that require the keyboard and mouse when correcting errors. While speech recognition can be a convenient alternative for traditional computer users, it can be a powerful tool for individuals with physical disabilities that limit their ability to use a keyboard and mouse. However, research into the performance, satisfaction, and usage patterns of individuals with physical disabilities has not been reported. In this article, we report on a study that provides initial insights into the efficacy of existing speech recognition systems with respect to individuals with physical disabilities. Our results confirm that productivity does not differ between traditional users and those with physical disabilities. In contrast, numerous differences were observed when users rated their satisfaction with the system and when usage patterns were analyzed. Published online: 18 May 2001     

基于PCA和LDA结合的人脸识别方法的比较研究

针对用于人脸识别的主分量分析(PCA)计算量大、识别效果不佳和分类时间长,线性判别分析(LDA)存在小样本问题,比较研究几种基于PCA和LDA的人脸识别方法,这些方法包括PCA+ LDA、2DPCA+ DLDA和2DPCA+2DLDA.在理论和实验上比较研究这些方法,且在ORL和Yale人脸库的实验数据表明,结合后的方法比结合前的方法分类效果好,分类时间短,且在这几种方法中,2DPCA+2DLDA的效果最佳.     

基于FPGA的并行总线QBus接口板的设计与实现

电子模块系统并行总线（QBus总线）是某型飞机火控电子设备的专用数据通信总线。研制QBus总线接口板用于QBus总线的总线控制、终端仿真及数据监控。介绍了QBus总线接口板的功能,给出了总体设计方案。采用自上向下（Top-Down）的EDA技术,逐步将问题细化,对各功能模块进行了详细划分和设计,用VHDL语言描述硬件电路,最终用FPGA实现了QBus总线技术。通过测试和联调,该板卡可以与某型飞机火控电子设备正常稳定通信。     

基于RTX和VMIC的虚拟试验联邦支撑环境研究

半实物试验对联邦支撑环境有毫秒级推进的需求,这一需求很难通过对网络环境的改善完成;针对原有基于VMIC的虚拟试验联邦支撑环境在操作系统环节的不确定性,提出了基于RTX操作系统和VMIC网络的实时扩展方案;分析了联邦运行必须的四大管理服务的模块划分,将不同模块划分到不同操作系统;针对时间服务的精度问题进行进一步研究,达到了毫秒级的时间推进;设计并实现了联邦支撑环境;对该环境的实际使用中的测试表明,其达到了半实物试验的要求。     

The Extended iSelf: The Impact of iPhone Separation on Cognition,Emotion, and Physiology

This study uniquely examined the effects on self, cognition, anxiety, and physiology when iPhone users are unable to answer their iPhone while performing cognitive tasks. A 2 x 2 within‐subjects experiment was conducted. Participants (N = 40 iPhone users) completed 2 word search puzzles. Among the key findings from this study were that when iPhone users were unable to answer their ringing iPhone during a word search puzzle, heart rate and blood pressure increased, self‐reported feelings of anxiety and unpleasantness increased, and self‐reported extended self and cognition decreased. These findings suggest that negative psychological and physiological outcomes are associated with iPhone separation and the inability to answer one's ringing iPhone during cognitive tasks. Implications of these findings are discussed.     

Online recruiting: The effects of organizational familiarity, website usability, and website attractiveness on viewers’ impressions of organizations

Previous research on Internet recruitment has made the implicit assumption that recruitment websites influence viewers’ opinions of recruiting organizations. This study tested this assumption using a pretest/posttest design. Findings revealed that participants’ organizational favorability, image as employer, and organizational attractiveness perceptions were affected by their viewing of organizational recruitment websites. Greater increases in favorable organizational evaluations from the pretest measures to the posttest measures occurred with organizations maintaining websites that were easy to navigate and/or that were appealing. Contrary to predictions made by signaling theory, recruitment websites had similar effects on the organizational impressions of all individuals, regardless of their familiarity with the organizations maintaining the recruitment websites that they viewed.     

Effects of computer-based testing on test performance and testing motivation

Computer-based testing (CBT) is a green computing strategies used to reduce paper consumption. However, some scholars have questioned the effectiveness of CBT and suggested for conducting systematic studies on CBT to carefully check its reliability and validity before opting for it. Recently, some studies have evaluated the effectiveness of CBT by comparing it with paper–pencil testing (PPT), and the findings were inconsistent. Besides this, most of these studies have been conducted using quasi or basic experimental designs without identifying testing effects on test takers. The limitation of these design is testing effects might occur when a participant in the control or treatment group is tested at least twice on a same test, and it influences the outcomes of taking a posttest, therefore, the findings might be misinterpreted. This study employed a Solomon four-group experimental design (2 × 3 factorial design) on a group of student teachers (n = 140) to compare CBT and PPT on test performance (test scores), testing time and testing motivation. Results indicated that the CBT mode is more reliable in terms of internal and external validity. The CBT significantly reduced testing time and developed stronger self-efficacy, intrinsic and social testing motivation in the participants.     

基于长短期记忆的流媒体QoE预测模型

现阶段关于连续性QoE预测模型研究存在着实时性差和精确度不高的问题。针对这些问题,提出L-QoE模型,一种使用长短期记忆(LSTM)网络的基于递归神经网络的QoE预测模型,用于捕获时变QoE中涉及的非线性和复杂时间依赖性。基于公开可用的连续QoE数据库的评估,实验结果表明,L-QoE模型能够有效模拟QoE动态性,得出更精确的预测结果。将所提模型与最近提出的QoE预测模型进行比较,通过对比得出该模型在数据库中突出的性能。     

The effect of testing location on usability testing performance, participant stress levels, and subjective testing experience

The effect of testing location on usability test elements such as stress levels and user experience is not clear. A comparison between traditional lab testing and synchronous remote testing was conducted. The present study investigated two groups of users in remote and traditional settings. Within each group participants completed two tasks, a simple task and a complex task. The dependent measures were task time taken, number of critical incidents reported, and user-reported anxiety score. Task times differed significantly between the physical location condition; this difference was not meaningful for real world application, and likely introduced by overhead regarding synchronous remote testing methods. Critical incident reporting counts did not differ in any condition. No significant differences were found in user reported stress levels. Subjective assessments of the study and interface also did not differ significantly. Study findings suggest a similar user testing experience exists for remote and traditional laboratory usability testing.     

Visual differentiation and recognition memory of look-alike drug names: effects of disfluent format,text enhancement and exposure time

Abstract

Three computer-based experiments were conducted to examine whether disfluent format, enhanced text, and increased exposure time improve the accuracy of visual differentiation and recognition memory of look-alike drug names. A three-way, repeated-measures look-alike drug name differentiation test assessed the visual differentiation accuracy of 30 nursing students (Experiment 1) and 15 nurses (Experiment 2). A two-way, repeated-measures recognition memory test examined the recognition memory accuracy of 15 nurses for look-alike drug names (Experiment 3). We found that making drug names disfluent did not significantly improve differentiation (Experiment 2) or memory accuracy (Experiment 3), but even impaired differentiation accuracy (Experiment 1). Enhanced text and longer exposure time significantly improved differentiation accuracy (Experiments 1 and 2). However, the enhanced text did not improve recognition memory (Experiment 3). We suggest that making look-alike drug names disfluent is not favourable. Enhanced text and longer exposure times are effective in supporting visual differentiation of look-alike drug names.

Practitioner Summary: Confusion arising from look-alike drug names may compromise patient safety. Three experiments examined the effects of disfluent format, text enhancement and increased exposure time on visual and memory performances. Making drug names more difficult to read did not improve performance. Enhancing text design and increasing exposure (i.e. reading) time improved visual differentiation between medications, but did not improve the recognition of medications from memory.

Abbreviations: SEEV: Salience-effort-expectancy-value; FDA: Food and Drug Administration; ANOVA: analysis of variance; SD: standard deviation, DF: disfluent format; TE: text enhancement; ET: exposure time.     

基于粗糙集的因果图方法简化研究

因果图方法是一种有效的软件测试方法,它适合于描述对于多种条件的组合、相应产生多个动作形式的测试用例设计,因果图最终被转换为判定表。在判定表中,测试用例的数目随输入数据数目的增加而线性地增加,当输入数据数目较大时,最终生成的判定表的规模会很大,相应的生成的测试用例会很多,并且,程序的规格说明中给出的有些条件及条件值并不是必需的,因此,文中采用粗糙集理论对因果图方法进行简化,并用一个实例说明了该简化方法的合理性和实用性。经简化,由因果图生成的判定表的条件和条件值都不再有冗余,所生成的测试用例数目大大减少,测试变得更加简洁有效。     

Effect of fault tolerance and communication delay on response time in a multiprocessor system with a bus topology

The effect of interprocessor communication and fault tolerance on the response time of N processors (nodes) interconnected through a bus type communication medium is discussed. Deterministic as well as probabilistic approaches are considered. Four correction methods to handle the unprocessed data by the faulty processor(s) are studied and compared. It is found that the effect of interprocessor communication and fault tolerance on the response time for communication-extensive programs (I/O bound) is more than that for computation-extensive programs (CPU bound). It is also found that the effect of fault tolerance on the response time is significant, and cannot be ignored when evaluating the performance of multiprocessor systems. We have shown that the work presented in this paper for a bus topology can be generalized and readily adopted by other multiprocessor network topologies.