scholarly journals Measures of the Benefit of Direct Encoding of Data Deltas for Data Pair Relation Perception

2019 ◽  
Author(s):  
Christine Nothelfer ◽  
Steven Franconeri
Keyword(s):  
Visual Processing ◽  
Response Times ◽  
Individual Data ◽  
Height Difference ◽  
Processing Efficiency ◽  
Data Value ◽  
Data Pair ◽  
Data Points ◽  
The Individual ◽  
Alternative Designs

The power of data visualization is not to convey absolute values of individual data points, but to allow the exploration of relations (increases or decreases in a data value) among them. One approach to highlighting these relations is to explicitly encode the numeric differences (deltas) between data values. Because this approach removes the context of the individual data values, it is important to measure how much of a performance improvement it actually offers, especially across differences in encodings and tasks, to ensure that it is worth adding to a visualization design. Across 3 different tasks, we measured the increase in visual processing efficiency for judging the relations between pairs of data values, from when only the values were shown, to when the deltas between the values were explicitly encoded, across position and length visual feature encodings (and slope encodings in Experiments 1 & 2). In Experiment 1, the participant’s task was to locate a pair of data values with a given relation (e.g., Find the ‘small bar to the left of a tall bar’ pair) among pairs of the opposite relation, and we measured processing efficiency from the increase in response times as the number of pairs increased. In Experiment 2, the task was to judge which of two relation types was more prevalent in a briefly presented display of 10 data pairs (e.g., Are there more ‘small bar to the left of a tall bar’ pairs or more ‘tall bar to the left of a small bar’ pairs?). In the final experiment, the task was to estimate the average delta within a briefly presented display of 6 data pairs (e.g., What is the average bar height difference across all ‘small bar to the left of a tall bar’ pairs?). Across all three experiments, visual processing of relations between data value pairs was significantly better when directly encoded as deltas rather than implicitly between individual data points, and varied substantially depending on the task (improvement ranged from 25% to 95%). Considering the ubiquity of bar charts and dot plots, relation perception for individual data values is highly inefficient, and confirms the need for alternative designs that provide not only absolute values, but also direct encoding of critical relationships between those values.

scholarly journals A Revised Framework to Evaluate the Consistency Assumption Globally in a Network of Interventions

2021 ◽  
pp. 0272989X2110680
Author(s):  
Loukia M. Spineli
Keyword(s):  
Complex Networks ◽  
Meta Analysis ◽  
Model Fit ◽  
Individual Data ◽  
Posterior Mean ◽  
Data Points ◽  
The Individual

Background The unrelated mean effects (UME) model has been proposed for evaluating the consistency assumption globally in the network of interventions. However, the UME model does not accommodate multiarm trials properly and omits comparisons between nonbaseline interventions in the multiarm trials not investigated in 2-arm trials. Methods We proposed a refinement of the UME model that tackles the limitations mentioned above. We also accompanied the scatterplots on the posterior mean deviance contributions of the trial arms under the network meta-analysis (NMA) and UME models with Bland-Altman plots to detect outlying trials contributing to poor model fit. We applied the refined and original UME models to 2 networks with multiarm trials. Results The original UME model omitted more than 20% of the observed comparisons in both networks. The thorough inspection of the individual data points’ deviance contribution using complementary plots in conjunction with the measures of model fit and the estimated between-trial variance indicated that the refined and original UME models revealed possible inconsistency in both examples. Conclusions The refined UME model allows proper accommodation of the multiarm trials and visualization of all observed evidence in complex networks of interventions. Furthermore, considering several complementary plots to investigate deviance helps draw informed conclusions on the possibility of global inconsistency in the network. Highlights We have refined the unrelated mean effects (UME) model to incorporate multiarm trials properly and to estimate all observed comparisons in complex networks of interventions. Forest plots with posterior summaries of all observed comparisons under the network meta-analysis and refined UME model can uncover the consequences of potential inconsistency in the network. Using complementary plots to investigate the individual data points’ deviance contribution in conjunction with model fit measures and estimated heterogeneity aid in detecting possible inconsistency.

Uncertainty of a Least Squares Curve Fit through Points with Known Uncertainties

1995 ◽  
Vol 23 (4) ◽  
pp. 315-326
Author(s):  
Ronald D. Flack
Keyword(s):  
Experimental Data ◽  
Least Squares ◽  
Fourth Order ◽  
Simulated Data ◽  
Higher Order ◽  
Individual Data ◽  
Linear Quadratic ◽  
Curve Fit ◽  
Data Points ◽  
The Individual

Uncertainties in least squares curve fits to data with uncertainties are examined. First, experimental data with nominal curve shapes, representing property profiles between boundaries, are simulated by adding known uncertainties to individual points. Next, curve fits to the simulated data are achieved and compared to the nominal curves. By using a large number of different sets of data, statistical differences between the two curves are quantified and, thus, the uncertainty of the curve fit is derived. Studies for linear, quadratic, and higher-order nominal curves with curve fits up to fourth order are presented herein. Typically, curve fits have uncertainties that are 50% or less than those of the individual data points. These uncertainties increase with increasing order of the least squares curve fit. The uncertainties decrease with increasing number of data points on the curves.

Effects of Symbol Structure on Visual Information Processing

1983 ◽  
Vol 27 (5) ◽  
pp. 354-354
Author(s):  
Bruce W. Hamill ◽  
Robert A. Virzi
Keyword(s):  
Information Processing ◽  
Visual Processing ◽  
Visual Information ◽  
Context Effects ◽  
Response Times ◽  
Search Time ◽  
Visual Information Processing ◽  
Array Size ◽  
Serial Search ◽  
Feature Structure

This investigation addresses the problem of attention in the processing of symbolic information from visual displays. Its scope includes the nature of attentive processes, the structural properties of stimuli that influence visual information processing mechanisms, and the manner in which these factors interact in perception. Our purpose is to determine the effects of configural feature structure on visual information processing. It is known that for stimuli comprising separable features, one can distinguish between conditions in which only one relevant feature differs among stimuli in the array being searched and conditions in which conjunctions of two (or more) features differ: Since the visual process of conjoining separable features is additive, this fact is reflected in search time as a function of array size, with feature conditions yielding flat curves associated with parallel search (no increase in search time across array sizes) and conjunction conditions yielding linearly increasing curves associated with serial search. We studied configural-feature stimuli within this framework to determine the nature of visual processing for such stimuli as a function of their feature structure. Response times of subjects searching for particular targets among structured arrays of distractors were measured in a speeded visual search task. Two different sets of stimulus materials were studied in array sizes of up to 32 stimuli, using both tachistoscope and microcomputer-based CRT presentation for each. Our results with configural stimuli indicate serial search in all of the conditions, with the slope of the response-time-by-array-size function being steeper for conjunction conditions than for feature conditions. However, for each of the two sets of stimuli we studied, there was one configuration that stood apart from the others in its set in that it yielded significantly faster response times, and in that conjunction conditions involving these particular stimuli tended to cluster with the feature conditions rather than with the other conjunction conditions. In addition to these major effects of particular targets, context effects also appeared in our results as effects of the various distractor sets used; certain of these context effects appear to be reversible. The effects of distractor sets on target search were studied in considerable detail. We have found interesting differences in visual processing between stimuli comprising separable features and those comprising configural features. We have also been able to characterize the effects we have found with configural-feature stimuli as being related to the specific feature structure of the target stimulus in the context of the specific feature structure of distractor stimuli. These findings have strong implications for the design of symbology that can enhance visual performance in the use of automated displays.

Telephone Conversations Affect the Executive but not the Alerting or Orienting Network

2021 ◽  
Author(s):  
Melina Kunar ◽  
Derrick Watson ◽  
Rhiannon Richards ◽  
Daniel Gunnell
Keyword(s):  
Visual Attention ◽  
Selective Attention ◽  
Mobile Phone ◽  
Dual Task ◽  
Response Times ◽  
Amount Of Information ◽  
Attentional Networks ◽  
Attention Tasks ◽  
Conflict Effect ◽  
The Individual

Previous work has shown that talking on a mobile phone leads to an impairment of visual attention. Gunnell et al. (2020) investigated the locus of these dual-task impairments and found that although phone conversations led to cognitive delays in response times, other mechanisms underlying particular selective attention tasks were unaffected. Here we investigated which attentional networks, if any, were impaired by having a phone conversation. We used the Attentional Network Task (ANT) to evaluate performance of the alerting, orienting and executive attentional networks, both in conditions where people were engaged in a conversation and where they were silent. Two experiments showed that there was a robust delay in response across all three networks. However, at the individual network level, holding a conversation did not influence the size of the alerting or orienting effects but it did reduce the size of the conflict effect within the executive network. The findings suggest that holding a conversation can reduce the overall speed of responding and, via its influence on the executive network, can reduce the amount of information that can be processed from the environment.

scholarly journals A Novel and Integrated Architecture for Securing Communication in IoT

2019 ◽  
Vol 9 (2) ◽  
pp. 924-929
Keyword(s):  
Energy Savings ◽  
Response Times ◽  
Security And Privacy ◽  
Iot Security ◽  
Authentication Mechanism ◽  
Use Of Data ◽  
Data Points ◽  
Integrated Architecture ◽  
Cost Efficient ◽  
Lightweight Encryption

Although the IoT opens the door to endless possibilities, but it is also associated with many risks because all devices connected to the internet involve the use of data points. Therefore, it is essential to ensure IoT security and privacy. A review of existing research works highlights the usage of traditional security scheme based on cryptography for data transmission among IoT nodes and gateways. The proposed system proposes an integrated model that combines lightweight encryption technique with robust and cost-efficient authentication mechanism. The proposed system introduces digital signature-based authentication and complexity minimization in order to resist the involvement of any kind of unknown attacks. The simulation outcome of this model exhibits reliable security, faster response times and energy savings for IoT nodes.

scholarly journals A Measure of the Interference Effect Distribution

2019 ◽  
Author(s):  
thibault gajdos ◽  
Mathieu Servant ◽  
Thierry Hasbroucq ◽  
Karen Davranche
Keyword(s):  
Experimental Data ◽  
Interference Effect ◽  
Graphical Representation ◽  
Response Times ◽  
Cognitive Model ◽  
Individual Data ◽  
Interference Effects ◽  
Distribution Index

We elaborated an index, the Interference Distribution Index, that allows to quantify the relation between response times and the size of the interference effect. This index is associated to an intuitive graphical representation, the Lorenz-interference plot. We show that this index has some convenient properties in terms of sensitivity to changes in the distribution of the interference effect and to aggregation of individual data. Moreover, it turns out that this index is the only one (up to an arbitrary increasing transformation) possessing these properties. The relevance of this index is illustrated through simulations of a cognitive model of interference effects and reanalysis of experimental data.

scholarly journals Perceptual insensitivity to higher-order statistical moments of coherent random dot motion

2018 ◽  
Author(s):  
Michael L. Waskom ◽  
Janeen Asfour ◽  
Roozbeh Kiani
Keyword(s):  
Visual Processing ◽  
Probability Distributions ◽  
Higher Order ◽  
Statistical Moments ◽  
Coherent Motion ◽  
It Use ◽  
Higher Order Moments ◽  
Dynamic Stimuli ◽  
Dot Motion ◽  
The Individual

ABSTRACTWhen the visual system analyses distributed patterns of sensory inputs, what features of those distributions does it use? It has been previously demonstrated that higher-order statistical moments of luminance distributions influence perception of static surfaces and textures. Here, we tested whether the brain also represents higher-order moments of dynamic stimuli. We constructed random dot kinematograms where dots moved according to probability distributions that selectively differed in terms of their mean, variance, skewness, or kurtosis. When viewing these stimuli, human observers were sensitive to the mean direction of coherent motion and to the variance of the individual dot displacement angles, but they were insensitive to skewness and kurtosis. Observer behavior accorded with a model of directional motion energy, suggesting that information about higher-order moments is discarded early in the visual processing hierarchy. These results demonstrate that use of higher-order moments is not a general property of visual perception.

Abstract P833: Standardized Protocols Reduce Response Times for LVO Strokes

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Vanesa K Vanderhye ◽  
Lynda Christel ◽  
Ali Turkmani ◽  
Kara A Sands
Keyword(s):  
Response Times ◽  
Vessel Occlusion ◽  
Early Reperfusion ◽  
Notification System ◽  
Stroke Treatment ◽  
Phone Calls ◽  
Data Points ◽  
Stroke Center ◽  
High Level ◽  
Cerebral Reperfusion

Introduction: Acute ischemic stroke treatment is time sensitive especially for large vessel occlusion (LVO) strokes with the goal to achieve early cerebral reperfusion. Research suggests standardized protocols incorporate early notification to reduce time from arrival to mechanical thrombectomy (MT). The MT workflow at a certified stroke center required multiple phone calls to mobilize staff and resources resulting in treatment delays. The average time from neurosurgery notification (NN) to case start (CST) was 60.4 minutes (min) resulting in average door-to-puncture (DTP) time of 124.8 min further delaying early reperfusion. Purpose: Standardize MT workflows and incorporate a 1-step notification system to reduce average NN to CST by 20% to 45 min to achieve 90 min average DTP time by 90 days post implementation. Methods: Baseline data for MT cases admitted 1/1/18 - 9/2/19 arriving in the emergency room (ER) and occurring inpatient were abstracted from stroke alert logs and the electronic health record. MT transfers were excluded. A multidisciplinary group of key stakeholders completed both high level process and workflow analysis maps and mock simulations to identify gaps. Both an analysis of variance and Tukey-Kramer’s T Test were performed revealing NN to CST was most statistically significant (p<.0001) and largest root cause for overall increased DTP times. New service-specific workflows were developed including 1-step notification activated via an existing group paging system used for other purposes. Activation notified on call staff of the MT case and patient location. Data points collected were NN to CST (ED and inpatient) and DTP (ED only). Results: Average NN to CST time was 26.7 min (33.3 min decrease or 55.1%; p<.0001, n=12) resulting in DTP average of 83.4 min (41.4 min decrease or 35.3%, n=10) 90 days post-implementation. The paging system was cost-neutral due to existing licensing agreements. Conclusion: In conclusion, streamlined workflows incorporating 1-step notification reduced time from notification to staff response so MT procedures could start sooner. A multidisciplinary approach along with key stakeholder buy-in was instrumental in successful project implementation.

Measuring Agreement Among Ranks

2016 ◽  
Vol 7 (1) ◽  
pp. 45-62 ◽  
Author(s):  
Kathleen Campbell Garwood ◽  
Alicia Graziosi Strandberg
Keyword(s):  
Specific Pattern ◽  
Comparison Methods ◽  
The People ◽  
Data Points ◽  
Good For ◽  
The Individual ◽  
Measuring Agreement ◽  
Different Sources ◽  
Kendall’S W

Is it possible to compare rankings from different sources when the individual rankings of the top x elements differ? To investigate this question, 2015 sustainable rankings from 4 sources that have ranked the top globally most sustainable corporations are considered (Corporate Knights, Fortune's World's Most Admired Companies, Newsweek's Green Rankings, and Harris). These rankings are analyzed using common rank comparison methods (Spearman's ?, Kendall's t). Then, they are analyzed to see if the sources ranking the data are doing so at random or if there is a specific pattern of agreement (Kendall's W and a method by Alvo, Cabilio & Feigin (1982)). The insights from these methods as well as possible limitations are considered. A truly sustainable corporation would transcend all definitions and be good for the environment and the people relying on the company. This paper will attempt to identify data points that tend to cluster close together in one or more groups, thereby justifying the feasibility of identifying sets of companies that are truly the “most” sustainable.

Extracting Visually Presented Element Relationships from Web Documents

2013 ◽  
Vol 7 (2) ◽  
pp. 13-29
Author(s):  
Radek Burget ◽  
Pavel Smrz
Keyword(s):  
Information Retrieval ◽  
World Wide ◽  
Visual Presentation ◽  
Generic Model ◽  
Individual Data ◽  
Web Documents ◽  
The World ◽  
Structured Information ◽  
The Individual ◽  
Document Format

Many documents in the World Wide Web present structured information that consists of multiple pieces of data with certain relationships among them. Although it is usually not difficult to identify the individual data values in the document text, their relationships are often not explicitly described in the document content. They are expressed by visual presentation of the document content that is expected to be interpreted by a human reader. In this paper, the authors propose a formal generic model of logical relationships in a document based on an interpretation of visual presentation patterns in the documents. The model describes the visually expressed relationships between individual parts of the contents independently of the document format and the particular way of presentation. Therefore, it can be used as an appropriate document model in many information retrieval or extraction applications. The authors formally define the model, the authors introduce a method of extracting the relationships between the content parts based on the visual presentation analysis and the authors discuss the expected applications. The authors also present a new dataset consisting of programmes of conferences and other scientific events and the authors discuss its suitability for the task in hand. Finally, the authors use the dataset to evaluate results of the implemented system.

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