Graphical Perception Research Articles

Towards a universal cognitive tool

Data visualization leverages human visual system to enhance cognition, it helps a person quickly and accurately see the trends, outliers, and patterns in data. Yet using visualization requires a viewer to read abstract imagery, estimate statistics, and retain information. These processes typically function differently for those with Intellectual and Developmental Disabilities (IDD) and have created an inaccessible barrier for them to access data. Preliminary findings from our graphical perception experiment suggest that people with IDD use different strategies to reason with data and are more sensitive to the design of data visualization compared with non-IDD populations. This article discusses several implications from that study and lays out actionable steps towards turning data visualization into a universal cognitive tool for people with varying cognitive abilities.

Local Banking to 45°: Axis Grid Generation for Line Charts

<p indent=0mm>Axis grid is a basic reference structure that assists people in reading line charts. In this paper, we focus on axis labels that help people perceive slopes in line charts. A series of user studies are conducted to explore the influence of local aspect ratio on the task of slope estimation in line charts. We evaluate the influence of different experimental conditions by calculating the errors between the user estimated slope and the ground truth. The results show that appropriate grid density and squarified grid aspect ratio increase the estimation accuracy of line segment slopes. Accordingly, we propose a new algorithm for generating axis grid considering the maximal label, the minimal label and label intervals for line charts. Following the previous criteria of simplicity, coverage and overlap, our algorithm applies the squarifed local aspect ratio to the joint optimization of the tick marks of both horizontal and vertical axis to generate aesthetic axis grid that helps increase graphical perception accuracy.

Investigation of human perception of tactile graphics and its dependence on fundamental friction mechanisms

Accurate depiction of visual information presents a formidable obstacle to the inclusion of people with visual impairments in standardized educational assessment. This challenge is often addressed by using tactile graphics, such as the use of a collection of tactile patterns representing various zones similar to the use of colors to represent political boundaries on a visual map. This study investigated friction mechanisms involved during fingertip exploration of tactile graphics, as well as the role that friction played in forming perceptions. Perception experiments were run using four texture types published by the Braille Authority of North America (BANA): two parallel-ridge textures of different ridge widths and spacings, and two ordered-dot textures of different dot spacings. To minimize tactile confusion, BANA guidelines prohibit the use of similar textures adjacent to each other. In this study, texture pairs were printed adjacent to each other on thermally activated (‘swell touch’) tactile paper. Sighted human subjects participated in a blinded task of determining if the two textures in the pair were the same or different. Friction measurements of the fingertip exploration of the texture pairs was recorded using a dynamometer in a range of normal loads from 0.4 to 0.8 N. A generalized linear model (GLM) with a logistic link function was used to predict the influence of texture pair and participant on the likelihood of perceiving each texture pair as the same or different. Results showed that the particular texture pair had a strong correlation to the ability of participants to discern between textures. These quantitative results support the BANA guidelines. The friction data showed that there was not a significant amount of difference among the coefficients of friction of various textures, such that COF was not a strong predictor of perceptive ability. However, there was some evidence that penetration of the fingertip between raised texture elements, and interlocking with these elements, allowed for dissimilar dot patterns to be better discerned than dissimilar ridge patterns. The results indicate that there are other aspects, possibly still tribological in nature, that govern tactile perception when exploring tactile graphics. These phenomena may include such things as finger deformation and vibrational response produced during contact with individual texture elements.

No mark is an island: Precision and category repulsion biases in data reproductions.

Data visualization is powerful in large part because it facilitates visual extraction of values. Yet, existing measures of perceptual precision for data channels (e.g., position, length, orientation, etc.) are based largely on verbal reports of ratio judgments between two values (e.g., [7]). Verbal report conflates multiple sources of error beyond actual visual precision, introducing a ratio computation between these values and a requirement to translate that ratio to a verbal number. Here we observe raw measures of precision by eliminating both ratio computations and verbal reports; we simply ask participants to reproduce marks (a single bar or dot) to match a previously seen one. We manipulated whether the mark was initially presented (and later drawn) alone, paired with a reference (e.g. a second '100%' bar also present at test, or a y-axis for the dot), or integrated with the reference (merging that reference bar into a stacked bar graph, or placing the dot directly on the axis). Reproductions of smaller values were overestimated, and larger values were underestimated, suggesting systematic memory biases. Average reproduction error was around 10% of the actual value, regardless of whether the reproduction was done on a common baseline with the original. In the reference and (especially) the integrated conditions, responses were repulsed from an implicit midpoint of the reference mark, such that values above 50% were overestimated, and values below 50% were underestimated. This reproduction paradigm may serve within a new suite of more fundamental measures of the precision of graphical perception.

Technical characteristics of the graphic perception of children's drawings.

The researcher examined the technical characteristics of the graphic perception of the children's drawings., the importance of research in revealing the technical characteristics of the graphic perception of the children's drawings has emerged, and the research objective has revealed the characteristics of the graphic perception of artistic expression in the drawings of children, the research studied the technical characteristics of children's drawings in His first study, the second one studied the characteristics of the graphic perception of children's drawings, consisted of the research community of the drawings of the children and the non-taking (20) of children (11) from the House of Buds for orphans and (9) from the House of Flowers for orphans in the Governorate of Babylon, and (30) of children who were not taken from three In the center of the province, the researcher used the descriptive approach in the method of analyzing the content and found several results discussed and conclusions, the most important of which is that the technical characteristics of the formal perception in the drawings of children are the following (repetition, exaggeration, flatness, wide space, land line The one, the lack of detail and the combination of drawing and writing, the researcher recommended several recommendations and suggested studies and confirmed the sources and supplements.

Common Fate for Animated Transitions in Visualization.

The Law of Common Fate from Gestalt psychology states that visual objects moving with the same velocity along parallel trajectories will be perceived by a human observer as grouped. However, the concept of common fate is much broader than mere velocity; in this paper we explore how common fate results from coordinated changes in luminance and size. We present results from a crowdsourced graphical perception study where we asked workers to make perceptual judgments on a series of trials involving four graphical objects under the influence of conflicting static and dynamic visual factors (position, size and luminance) used in conjunction. Our results yield the following rankings for visual grouping: motion > (dynamic luminance, size, luminance); dynamic size > (dynamic luminance, position); and dynamic luminance > size. We also conducted a follow-up experiment to evaluate the three dynamic visual factors in a more ecologically valid setting, using both a Gapminder-like animated scatterplot and a thematic map of election data. The results indicate that in practice the relative grouping strengths of these factors may depend on various parameters including the visualization characteristics and the underlying data. We discuss design implications for animated transitions in data visualization.

Evaluating 'Graphical Perception' with CNNs.

Convolutional neural networks can successfully perform many computer vision tasks on images. For visualization, how do CNNs perform when applied to graphical perception tasks? We investigate this question by reproducing Cleveland and McGill's seminal 1984 experiments, which measured human perception efficiency of different visual encodings and defined elementary perceptual tasks for visualization. We measure the graphical perceptual capabilities of four network architectures on five different visualization tasks and compare to existing and new human performance baselines. While under limited circumstances CNNs are able to meet or outperform human task performance, we find that CNNs are not currently a good model for human graphical perception. We present the results of these experiments to foster the understanding of how CNNs succeed and fail when applied to data visualizations.

Formalizing Visualization Design Knowledge as Constraints: Actionable and Extensible Models in Draco.

There exists a gap between visualization design guidelines and their application in visualization tools. While empirical studies can provide design guidance, we lack a formal framework for representing design knowledge, integrating results across studies, and applying this knowledge in automated design tools that promote effective encodings and facilitate visual exploration. We propose modeling visualization design knowledge as a collection of constraints, in conjunction with a method to learn weights for soft constraints from experimental data. Using constraints, we can take theoretical design knowledge and express it in a concrete, extensible, and testable form: the resulting models can recommend visualization designs and can easily be augmented with additional constraints or updated weights. We implement our approach in Draco, a constraint-based system based on Answer Set Programming (ASP). We demonstrate how to construct increasingly sophisticated automated visualization design systems, including systems based on weights learned directly from the results of graphical perception experiments.

Следственный осмотр — лишнее звено в механизме приобщения вещественных доказательств к материалам уголовного дела

Purpose. doctrinal and statutory analysis of the essence of an investigatory examination aimed at identification of theoretical, legislative and applied issues arising in the course of acknowledging objects or documents as material evidence in a criminal case and elaboration of ways and means of their elimination and solution. Methodology: dialectics, analysis, synthesis, historical and legal method, system research method. Conclusions. 1) The scientific doctrine and the criminal procedure laws based on it combine two various forms of cognition of criminal case circumstances: a) an examination as a non-verbal investigatory action aimed at visual and graphic perception of material fragments of objective reality and b) further research of such fragments accompanied by formal and logical thinking and ending with coming to specific conclusions. 2) Primarily, an investigator has to attempt not at an examination of an object or a document rather at its safekeeping within a criminal case, ensuring an opportunity of its further research in the original state, in particular, in a court hearing. 3) An examination as a standalone investigatory action is an excess link in the mechanism of acknowledging objects or documents as material evidence stipulated by Part 2 Article 81 of the Criminal Procedure Code of the Russian Federation except for the cases when it is impossible to ensure their safekeeping up to the termination of the criminal case proceedings. Scientific and practical significance. The conducted research may be useful for scientists, students, postgraduate students and junior scientific assistants, practitioners and everyone interested in the issues of the investigatory action carrying out.

Assessing the Graphical Perception of Time and Speed on 2D+Time Trajectories.

We empirically evaluate the extent to which people perceive non-constant time and speed encoded on 2D paths. In our graphical perception study, we evaluate nine encodings from the literature for both straight and curved paths. Visualizing time and speed information is a challenge when the x and y axes already encode other data dimensions, for example when plotting a trip on a map. This is particularly true in disciplines such as time-geography and movement analytics that often require visualizing spatio-temporal trajectories. A common approach is to use 2D+time trajectories, which are 2D paths for which time is an additional dimension. However, there are currently no guidelines regarding how to represent time and speed on such paths. Our study results provide InfoVis designers with clear guidance regarding which encodings to use and which ones to avoid; in particular, we suggest using color value to encode speed and segment length to encode time whenever possible.

A Graphical-based educational simulation tool for Wireless Sensor Networks

Many routing protocols have been developed to improve the lifetime, bandwidth reusability and scalability of the Wireless Sensor Networks (WSNs). The operation of routing protocols is difficult to understand and some problems may occur while developing these protocols. Simulation is a relatively fast way of estimating these protocols and understating what is happening in the network. Thus, this paper presents an open source Graphical-based educational simulation tool called Gbest-WSN for simulating routing protocols of the static and mobile, homogeneous and heterogeneous WSNs. Gbest-WSN tool has a user-friendly interface that helps the user to select the routing protocol and define the network configuration. It is provided with four routing protocols; namely LEACH, LEACH-Mobile, immune algorithm-based and genetic algorithm-based routing protocols. Also, it allows the user to update the existing routing protocols and add a new routing protocol. Gbest-WSN is provided with radio, coverage and mobility models for modeling the hardware of the sensor node. It shows a detailed 2D and 3D graphical perception for what is happing during the routing process. Also, it has the ability to compare the simulation results of different simulation methods or different network configurations. In addition, it allows the user to save and load simulation scenarios and also exports the graphical results on PDF files and the statistical results on excel or mat files. Moreover, Gbest-WSN is provided with html help documents to help the user how to use it. The illustrative simulation examples clarified that the Gbest-WSN is a helpful tool for the students, teachers and researchers who work in the field of WSNs.

Historical Citation and Revolutionary Epistemology

This article defends the thesis that there are multiple points of exchange between the categories of “word” and “image” in Walter Benjamin’s Arcades Project. Benjamin describes the truth of the articulate wish of the past as “graphically perceptible” and the image as “readable.” In this respect the vocabulary of “word” and “image” that Benjamin’s early work had opposed are not just deployed in concert, but specific features of the vocabulary of “word” and “image” become exchangeable. The distinctive features of this exchange can be used to expound on Benjamin’s peculiar understanding of revolutionary experience and the significance of the break that it marks with his early way of opposing the word and the image. In particular, the exchange of features between word and image can explain the mechanics and intended effect of his idea that the meaning of history can be perceived in an image. The study of this exchange also shows that although the framework of “graphic perception” entails an experience of motivating meaning that is epistemologically grounded, the citation model of history is unable to secure the extension of the sought after legibility of the nineteenth century to a recipient.

Four Experiments on the Perception of Bar Charts

Bar charts are one of the most common visualization types. In a classic graphical perception paper, Cleveland & McGill studied how different bar chart designs impact the accuracy with which viewers can complete simple perceptual tasks. They found that people perform substantially worse on stacked bar charts than on aligned bar charts, and that comparisons between adjacent bars are more accurate than between widely separated bars. However, the study did not explore why these differences occur. In this paper, we describe a series of follow-up experiments to further explore and explain their results. While our results generally confirm Cleveland & McGill's ranking of various bar chart configurations, we provide additional insight into the bar chart reading task and the sources of participants' errors. We use our results to propose new hypotheses on the perception of bar charts.

Task-Driven Evaluation of Aggregation in Time Series Visualization.

Many visualization tasks require the viewer to make judgments about aggregate properties of data. Recent work has shown that viewers can perform such tasks effectively, for example to efficiently compare the maximums or means over ranges of data. However, this work also shows that such effectiveness depends on the designs of the displays. In this paper, we explore this relationship between aggregation task and visualization design to provide guidance on matching tasks with designs. We combine prior results from perceptual science and graphical perception to suggest a set of design variables that influence performance on various aggregate comparison tasks. We describe how choices in these variables can lead to designs that are matched to particular tasks. We use these variables to assess a set of eight different designs, predicting how they will support a set of six aggregate time series comparison tasks. A crowd-sourced evaluation confirms these predictions. These results not only provide evidence for how the specific visualizations support various tasks, but also suggest using the identified design variables as a tool for designing visualizations well suited for various types of tasks.

Culture and Graphic Symbols in Augmentative and Alternative Communication (AAC)

Graphic symbols are useful for individuals with complex communication in use of Augmentative and Alternative Communication (AAC). Brown (1977, 1978) hypothesized that the iconicity of graphic symbols was culture bound. Last decades, cross-cultural studies have been implemented suggesting that the cultural background of an AAC user might have an important influence on his or her symbol perception and use of graphic symbols. The purpose of this study is to analyze research literature on cross-cultural issues after 1977 and aspects of graphic symbols in AAC using systematic review method. As a result, findings from eleven papers on cross-cultural issues of graphic symbols in AAC supported the possibility of culture-bound in graphic symbol perception. Directions for future research are presented based on identified research gaps.

A course in constructing effective displays of data for pharmaceutical research personnel

Interpreting data and communicating effectively through graphs and tables are requisite skills for statisticians and non-statisticians in the pharmaceutical industry. However, the quality of visual displays of data in the medical and pharmaceutical literature and at scientific conferences is severely lacking. We describe an interactive, workshop-driven, 2-day short course that we constructed for pharmaceutical research personnel to learn these skills. The examples in the course and the workshop datasets source from our professional experiences, the scientific literature, and the mass media. During the course, the participants are exposed to and gain hands-on experience with the principles of visual and graphical perception, design, and construction of both graphic and tabular displays of quantitative and qualitative information. After completing the course, with a critical eye, the participants are able to construct, revise, critique, and interpret graphic and tabular displays according to an extensive set of guidelines.

Data display format and hospital ward reports: effects of different presentations on data interpretation

Graphs are often used in medical communication, both in clinical practice and health management. They can help the processing of quantitative information but may also contribute to drawing wrong conclusions. The aim of the survey is to study the graphical perception of the data at the management level and its possible effects, showing how some criteria of appraisal of a phenomenon are influenced by the graphical format. One hundred and five medical doctors and health direction professionals of hospitals in Naples, Rome, Siena and Turin were interviewed. Four different graphs or table related to the same hypothetical data on average hospital stay in the period January 2000 to September 2003 were shown to participants, and their impressions were recorded. Less than one-fourth of the participants understood that the data set was the same for the different diagrams. The process of understanding is mostly correlated with being a director, having a degree in medicine and working in central-northern cities. The table seems easier for interpretation (98.1%), more suitable (84.8%), more used (92.4%) and more pleasant than other data presentation. On the other hand radar format had worse results in all questions. The choice of a graphical format may influence the understanding of data. Further research is needed in order to sustain the improvement of medical and health professionals' knowledge in the display data format.

A Study on Dual-Scale Data Charts

We present the results of a user study that compares different ways of representing Dual-Scale data charts. Dual-Scale charts incorporate two different data resolutions into one chart in order to emphasize data in regions of interest or to enable the comparison of data from distant regions. While some design guidelines exist for these types of charts, there is currently little empirical evidence on which to base their design. We fill this gap by discussing the design space of Dual-Scale cartesian-coordinate charts and by experimentally comparing the performance of different chart types with respect to elementary graphical perception tasks such as comparing lengths and distances. Our study suggests that cut-out charts which include collocated full context and focus are the best alternative, and that superimposed charts in which focus and context overlap on top of each other should be avoided.

Fast hologram generation method for interactive holographic VR-CAD system

In a Virtual Reality based Computer-Aided Design (VR-CAD) system, the designer creates three-dimensional shapes using human–computer interaction (HCI) technique such as voice commands, hand motions, and finger motions. In this system, 3-D displays can provide the visual feedback to the designer a realistic graphical perception about the part she/he is designing. Especially, holographic method is particularly regarded as one of the most attractive approaches for creating the most authentic illusion of observing volumetric objects. Therefore, holographic 3-D display is the most suitable method for the VR-CAD system. Therefore, in this paper, we propose the fast generation method of 3-D hologram pattern using spatio-temporal redundant data of 3-D scene in VR-CAD system. Some experiments are carried out and its results are comparatively discussed with those of the conventional methods in terms of computational speed and required memory space.

Graphical Perception of Multiple Time Series

Line graphs have been the visualization of choice for temporal data ever since the days of William Playfair (1759-1823), but realistic temporal analysis tasks often include multiple simultaneous time series. In this work, we explore user performance for comparison, slope, and discrimination tasks for different line graph techniques involving multiple time series. Our results show that techniques that create separate charts for each time series--such as small multiples and horizon graphs--are generally more efficient for comparisons across time series with a large visual span. On the other hand, shared-space techniques--like standard line graphs--are typically more efficient for comparisons over smaller visual spans where the impact of overlap and clutter is reduced.