The effects of color combinations,luminance contrast,and area ratio on icon visual search performance

The visual search of icons in a digital interface plays an important role in human-computer interaction. In this behavior study about the visual search of graphic symbols, the effects of the color combination, luminance contrast, and icon area ratio were investigated. A total of 28 participants (12 men and 16 women, ages ranging from 20 to 28 years, Mean = 22.4, SD = 1.7) were asked to perform an icon search task. Participants’ icon search accuracy and response times were measured as a function of the following independent variables: three levels of area ratios, four background colors, four foreground colors, and three levels of luminance contrast. The results showed that although there was no significant main effect of luminance contrast on the icon search accuracy, participants responded more quickly to medium luminance contrast than low or high luminance contrast. Similarly, the medium or low area ratio was more conducive to the participants identifying icons. Moreover, a strong interaction was observed between the effects of luminance contrast and icon area ratio. The icon search performance of the high luminance contrast improved significantly as the figure/background area ratio decreased. Icon color combinations also significantly affected visual search performance. White on black, yellow on black, turquoise on black, white on red, yellow on red, and white on purple resulted in better performance than other color combinations. The findings of this study provide useful guidelines for designing more efficient and user-friendly icons and interfaces in the future.     

The effects of icon internal characteristics on complex cognition

The interaction between humans and digital interfaces is a complex cognitive process which has a high demand on working memory resources. However, most previous research on icon perception seems to focus only on the influences of an icon's internal characteristics (e.g. visual complexity, concreteness and familiarity) on simple tasks such as visual search and recall tasks. The study reported here applied a math task to simulate the complicated process of human-computer interaction and investigated the effects of icon internal characteristics on the performance of complex cognition. First, we created and filtered 80 novel icons of 4 different types (simple & concrete, simple & abstract, complex & concrete, complex & abstract). Subsequently, participants were required to perform an icon-meaning recall task, during which icon familiarity was manipulated by different exposure frequencies. Finally, after viewing random icon-digit associations, participants' abilities to solve algebraic equations involving icons were tested. The results indicated that participants performed significantly better when the icons were simple, concrete or familiar and these beneficial effects increased as the task became more complex. Additionally, strong evidence was found to show that it was easier to encode and maintain familiar icons and associated information in working memory. The findings of this study provide useful information for the icon design and interface design of human-computer interaction.     

Icon identification in context: the changing role of icon characteristics with user experience

OBJECTIVE: This research examined the relative importance of icon characteristics in determining the speed and accuracy of icon identification. BACKGROUND: Studies to date have focused on the role of one or two icon characteristics when users first experience an icon set. This means that little is known about the relative importance of icon characteristics or how the role of icon characteristics might change as users gain experience with icons. METHODS: Thirty participants carried out an icon identification task over a long series of trials to simulate learning through experience. Icon characteristics investigated included semantic distance, concreteness, familiarity, and visual complexity. RESULTS: Icon characteristics were major determinants of performance, accounting for up to 69% of the variance observed in performance. However, the importance of icon characteristics changed with experience: Semantic distance is crucial initially while icon-function relationships are learned, but familiarity is important later because it has lasting effects on access to long-term memory representations. CONCLUSION: These findings suggest that icon concreteness may not be of primary importance when identifying icons and that semantic distance and familiarity may be more important. APPLICATION: Designers need to take into account icon characteristics other than concreteness when creating icons, particularly semantic distance and familiarity. The precise importance of the latter characteristics will vary depending on whether icons are rarely encountered or frequently used.     

Effects of computer icons and figure/background area ratios and color combinations on visual search performance on an LCD monitor

This study investigated the effects of figure/background color combinations, the type of computer icon and the figure/background area ratio on visual search performance on a liquid crystal display (LCD) screen. Participants had to search for the target item in a circle stimulus array, which had a diameter of 20 cm and included one target and 19 distracters. Results showed that these three independent variables significantly affected the visual search performance. The search times for EMAIL and SAVE computer icons were significantly shorter than that for a PRINT computer icon. Visual search performance was better for computer icons with a 90% figure/background area ratio than for a 70% ratio. However, no difference in search time between 90% and 50% ratios or between 70% and 50% ratios was observed. Color combinations also significantly affected the visual search performance and white/yellow and white/blue color combinations for the figure/background resulted in better performance than black/blue and black/yellow combinations. However, no difference in search time was observed for participants with and without esthetic training. The implications of the results are applicable to design icons for the interfacing of computers and communication information.     

Is visual content in textual search interfaces beneficial to dyslexic users?

Dyslexia is a learning disability characterised by problems with accurate or fluent word recognition, poor decoding, and poor spelling abilities. Although several studies have addressed dyslexia and Web accessibility, less is known about how dyslexia affects information search. This study investigated whether the inclusion of icons in search user interfaces enhances performance among dyslexics. A total of 21 dyslexics and 21 controls completed 52 search tasks in 4 conditions: icons only, words only, and both icons and words in a grid layout and a list layout, while eye movements were recorded. Dyslexics took significantly longer than controls to locate targets in tasks containing text, but not in the icon-only condition. Dyslexics had longer fixation durations than controls in both icon and text based search arrays, suggesting higher mental load associated with search tasks generally. The addition of words to icon arrays led to faster search times within controls, but not dyslexics. Dyslexics also exhibited more fixations on dual-modality tasks, and longer scanpaths than controls in list layout. Both groups were fastest searching the list layout, with icons and words listed in columns. Results are discussed in terms of the design of accessible search interfaces for dyslexic users, taking into account mental load of dual-modality information display, and the arrangement of search items. Empirical data is provided for the design of accessible search results interfaces for dyslexics.     

Effect of answer format and review method on college students' learning

Interactive instructional methods are characterized by engaging students with the course material and involve delivering feedback for their efforts. Using a mixed 2 × 2 factorial experiment, we compared the effects of multiple choice answer formats (word versus letter) and methods (automated versus manual) on 70 undergraduate students' acquisition of instructional material. Although there was no significant difference in participants' gain scores between automated (“clickers”) and manual (holding up response cards) methods, significantly greater learning occurred when participants used the word rather than letter answer format. Despite participants' preference for letter over word format, instructors may still want to require students to write out answers to review questions given the improved performance it yields.     

Using icons to convey medication schedule information

We examined older adult comprehension and memory for medication schedules conveyed by different types of visual icons as well as text. Three icons were compared: a timeline, a pair of 12 h clocks (one for AM and one for PM hours) and a 24 h clock. In Experiment 1, older and younger participants paraphrased and then recalled schedules that were conveyed by the three icons or by text. Text and timeline schedules were paraphrased more accurately than either clock icon. Paraphrase errors suggested that subjects had trouble integrating schedule information across the two 12 h clocks. Analysis of paraphrase times showed that the text schedule was paraphrased most quickly, followed by the timeline, the 24 h clock and the 12 h clock. No differences were found for the accuracy of recalling the icon and text schedules. Experiment 2 examined free and cued recall after limited study time by older adults. Because text superiority in Experiment 1 may have reflected greater familiarity with text than with icons, recall was examined across four trials in Experiment 2. Text was recalled most accurately, followed by the timeline, the 24 h clock and the 12 h clock. Study-test trials did not influence recall. Text schedules may have been generally more effective than the icons because of their greater familiarity. The timeline may have been the most effective icon because it was more compact and familiar than the clock icons used in the study. The findings suggest that including such icons in medication instructions requires training.     

Evidence for global feature superiority in menu selection by icons

A search-and-select paradigm was adopted to investigate which visual characteristics of icons are relevant for menu selection. Two icon sets (abstract icons, representational icons) were compared to a word command set. For abstract icons, global features were used in order lo maximize their visual distinctiveness. For representational icons local features were used in order to ensure a high degree of representativeness and a small “articulatory distance”. Results revealed that abstract icons were searched and selected much faster than both word commands and representational icons. In addition, response time functions indicated that abstract icons can be searched in parallel (no effect of menu size) whereas word commands and representational icons have to be searched sequentially. Error rates were small in all conditions, and there was no indication of a speed-accuracy tradeoff. Thus, when icons are used in menu selection, visual distinctiveness (due to global features) seems to override respresentativeness (due to local features).     

Designing haptic icons to support collaborative turn-taking

This paper describes research exploring the use of haptics to support users collaborating remotely in a single-user shared application. Mediation of turn-taking during remote collaboration provides a context to explore haptic affordances for background communication as well as control negotiation in remote collaboration: existing turn-taking protocols are rudimentary, lacking many communication cues available in face-to-face collaboration. We therefore designed a custom turn-taking protocol that allows users to express different levels of urgency in their request for control from a collaborator; state of control and requests are communicated by touch, with the intent of offloading visual attention. To support it, we developed a set of haptic icons, tangible stimuli to which specific meanings have been assigned.Because we required an icon set which could be utilized with specified, varying levels of intrusiveness in real attentionally challenged situations, we used a perceptually guided procedure that consisted of four steps: initial icon set design, perceptual refinement, validation of learnability and effectiveness under workload, and deployment in an application simulation. We found that our haptic icons could be learned to a high degree of accuracy in under 3 min and remained identifiable even under significant cognitive workload. In an exploratory observational study comparing haptic, visual, and combined haptic and visual support for our protocol, participants overall preferred the combined multi-modal support, and in particular preferred the haptic support for control changes and the visual support for displaying state. In their control negotiation, users clearly utilized the option of requesting with graded urgency. The three major contributions in this paper are: (1) the introduction and first case study using a systematic process for refining and evaluating haptic icons for background communication in a primarily visual application; (2) the usability observed for a particular set of icons designed with that process; and (3) the introduction of an urgency-based turn-taking protocol and a comparison of haptic, visual and multi-modal support of our implementation of that protocol.     

Age-related differences in the initial usability of mobile device icons

Mobile devices offer much potential to support older adults (age 65+). However, older adults have been relatively slow to adopt mobile devices. Although much ongoing HCI research has examined usability problems to address this issue, little work has looked at whether existing graphical icons are harder to use for this population compared with younger adults. We conducted a qualitative exploratory study and a follow-up experimental study to determine which icon characteristics help initial icon usability for older adults. We found that our older participants did have more problems using existing mobile device icons, but that particular icon characteristics – semantically close meaning (i.e. natural, close link between depicted objects and associated function), familiar, labelled and concrete (i.e. those depicting real-world objects) – improved icon usability for them. We discuss how these findings can help icon designers to create mobile device icons that are more suited to the abilities and technology experience of older adults.     

Development and validation of icons varying in their abstractness

Icons are used widely in human-computer interfaces. The level of abstractness-concreteness of an icon and its effect upon performance is of widespread interest. The authors have devised a quantitative measure for abstractness based on the complexity of the icon. They test their metric against subjective judgments of abstractness as identified by two different groups of subjects. After ranking two sets of ‘abstract’ and ‘concrete’ icons, the authors examined how well the icons were matched to the Pascal constructs that they represented. Further experiments were conducted using different groups of subjects to check whether correct matching of the icons with constructs was influenced by context. In summary the authors found that their metric was a good match for subjective measures of abstractness-concreteness. They also found that there is a better identification of concrete icons than abstract icons. Finally, it was shown that context does affect the correct identification of icons.     

Effects of visual field,exposure time,and set size on icon search with varied delays using an LCD monitor

Abstract— This study investigated the effects of visual field (left or right), exposure time, and set size on icon search with varied delay times. Nineteen women and 17 men, who were Taiwanese graduate students aged 24–40 years, participated. Participants were told to search for a target icon in a circular stimulus array, which had a diameter of 7 cm and included five, seven, or nine items. The results indicated that set size significantly affected search time. Search time was significantly longer for a nine‐icon set than for five and seven icons. Search times were significantly longer for 5‐sec delays than for 3‐and 1 ‐sec delays. However, exposure time and visual field did not significantly affect search time. Results showed that set size significantly affected accuracy. The accuracy for the five‐icon condition was greater than that for the seven‐ and nine‐icon conditions. Moreover, accuracy was greater for 1 ‐ than for 3‐ and 5‐sec‐delay conditions. However, no significant effect on accuracy was found for visual field or exposure time. Finally, search times for correct and incorrect responses were analyzed separately. The results are applicable to graphics‐based interface design.     

图符一致性对识别效率及可靠性的影响

针对已有研究对图符一致性的影响考虑还不充分的不足,采用被试内实验设计,研究了人机界面图符一致性对识别效率及可靠性的影响。实验共分五组：实验一建立图符形状与指代功能之间的联系（建立用户心理模型）;实验二考察图符外观/形状一致性的影响;实验三考察功能按键位置一致性的影响;实验四和实验五考察图符外观/形状与功能/语义匹配一致性的影响。五组实验的错误率差异的卡方检验结果为：实验四＞实验五=实验三=实验二=实验一;反应时差异的单因素方差分析结果为：实验五=实验四＞实验三=实验二=实验一。结论：外观/形式与功能/语义的“匹配/对应”是界面一致性的核心。相似图符形状指代原有功能时,识别存在学习的正迁移;图符外观一致而指代的功能不一致或反之（新图符指代原有功能）时,识别则会由于心理模型冲突而造成学习的负迁移,表现为识别效率和可靠性的降低。     

汉语语音检索的集外词问题与两阶段检索方法

该文针对大规模汉语语音检索任务提出汉语语音检索中的集外词问题和针对集外查询词的两阶段检索方法。汉语语音识别和检索中,集外词可以以词表词序列的形式被识别和检索到,因此被认为不存在集外词问题;该文发现集外查询词性能远远低于集内查询词,将此问题定义为汉语语音检索任务的集外词问题,并提出两阶段的检索方法,第一阶段通过模糊音素匹配的方法提高查全率,第二阶段通过词格修正的方法提高查准率。实验表明,两阶段的检索方法极大的提高了典型集外查询词的检索性能,FOM指标相对基线系统提高了24.1%。     

Displaying uncertainty: investigating the effects of display format and specificity

We conducted four studies regarding the representation of probabilistic information. Experiments 1 through 3 compared performance on a simulated stock purchase task, in which information regarding stock profitability was probabilistic. Two variables were manipulated: display format for probabilistic information (blurred and colored icons, linguistic phrases, numeric expressions, and combinations) and specificity level (in which the number and size of discrete steps into which the probabilistic information was mapped differed). Results indicated few performance differences attributable to display format; however, performance did improve with greater specificity. Experiment 4, in which participants generated membership functions corresponding to three display formats, found a high degree of similarity in functions across formats and participants and a strong relationship between the shape of the membership function and the intended meaning of the representation. These results indicate that participants can successfully interpret nonnumeric representations of uncertainty and can use such representations in a manner similar to the way numeric expressions are used in a decision-making task. Actual or potential applications of this research include the use of graphical representations of uncertainty in systems such as command and control and situation displays.     

Feature Extraction using Unit-linking Pulse Coupled Neural Network and its Applications

In this paper, we use Unit-linking PCNN (Pulse Coupled Neural Network), the simplified model of PCNN consisting of spiking neurons, to code a 2-dimensional image into a 1-dimensional time sequence called global Unit-linking PCNN image icon or time signature, including features of the original image and having the translation, rotation, and scale invariance. Dividing an image into multiple parts can obtain local Unit-linking PCNN image icons corresponding to the image’s local regions, which can reflect the local changes of the image. In the meantime, the global and the local Unit-linking PCNN image icons are used in navigation, object detection, and image authentication. In navigation, global Unit-linking PCNN image icon shows qualified performance especially in non-stationary-video navigation. Object detection using global Unit-linking PCNN image icon, is independent of variances of translation, rotation, and scale, and object segmentation is avoided. In image authentication, using local Unit-linking PCNN image icon can authenticate correctly some juggled images failed to authenticate by using local histogram or local mean intensity, and can locate the juggled positions in the juggled images with some accuracy.     

A usability comparison of three alternative message formats for an SMS banking service

The study reported here compares the usability of three types of message input format: Abbreviations, Numbers and Free-Form as alternatives for a Pull SMS banking service. Participants (N=74) used all three formats to carry out three banking transactions in a repeated measures experiment. The Abbreviations and Numbers versions of the service performed to generally equal levels in all metrics. Free-Form performed the worst as participants took significantly longer to complete tasks and it received significantly lower overall questionnaire and quality scores for satisfaction. The older age group found all three versions in general to be less usable than the younger age group. They took longer on the tasks, had lower completion rates and they also gave each version a lower overall mean satisfaction score.     

An experimental research study on the effect of pictorial icons on a user-learner’s performance

This experimental counterbalanced repeated measures study on the effect of three types of icons (abstract, pictorial and drawing) on the learning and performance of two types of learners (abstract and concrete) was conducted during the Spring 2000–Spring 2001 semesters at the University of Central Florida. The counterbalanced lesson followed by a counterbalanced and completely randomized quiz on three levels was field tested in the Spring–Summer 2000 on 37 UCF graduate students and final tested in the Fall 2000–Spring 2001 on 53 UCF graduate student subjects. A general linear model repeated measures ANOVA revealed that icon type had a significant effect on the learning and performance of both types of learners. Pictorial icons resulted in best scores. No significant interaction was found between icon type and learner type even though on a matched condition, abstract learners with abstract icon resulted in better scores than when concrete learners were matched with concrete (pictorial and drawing) icons. Implications for future research are drawn as well as practical applications identified in the field of teaching, learning, training and performance.     

Influence mechanism of icon semantics on visual search performance: Evidence from an eye-tracking study

Explicit icon semantics can reduce the difficulty of understanding complex visual information. Optimizing the icon semantics and text semantics of icons can effectively improve the cognitive performance of digital interfaces. This paper adopts visual search tasks to study the effects of different combinations of icon semantic familiarity and the presence or absence of text on icon search performance under horizontal and vertical layouts. The behavioral experiment results show that under two layouts: 1. The main effect of icon semantics is significant, and the search performance increases with the increase of semantic familiarity. 2. The main effect of text is significant, and the search performance is negatively correlated with the addition of text. The eye movement experiment found that the semantic familiarity of icons had a significant impact on average fixation time. Furthermore, the number of fixation points changed significantly after the text variable was added. Therefore, there was no significant difference in the number of fixation points in the horizontal layout, and icon semantics was the main influencing factor in visual search. In the vertical layout, there was no significant difference in average fixation time, and text was the main influencing factor of visual search. The results show that the semantic familiarity of icons and different combinations with or without text significantly affect visual search performance in horizontal and vertical layouts. This paper provides a theoretical reference for the combination of icons and text in interface design.     

Semantic congruency of auditory warnings

Abstract

The aim of this study was to explore operator experience and performance for semantically congruent and incongruent auditory icons and abstract alarm sounds. It was expected that performance advantages for congruent sounds would be present initially but would reduce over time for both alarm types. Twenty-four participants (12M/12F) were placed into auditory icon or abstract alarm groupings. For each group both congruent and incongruent alarms were used to represent different driving task scenarios. Once sounded, participants were required to respond to each alarm by selecting a corresponding driving scenario. User performance for all sound types improved over time, however even with experience a decrement in speed of response remained for the incongruent iconic sounds and in accuracy of performance for the abstract warning sounds when compared to the congruent auditory icons. Semantic congruency was found to be of more importance for auditory icons than for abstract sounds.

Practitioner Summary: Alarms are used in many operating systems as emergency, alerting, or continuous monitoring signals for instance. This study found that the type and representativeness of an auditory warning will influence operator performance over time. Semantically congruent iconic sounds produced performance advantages over both incongruent iconic sounds and abstract warnings.