Visualizing Sets with Linear Diagrams.

This paper presents the first design principles that optimize the visualization of sets using linear diagrams.These principles are justified through empirical studies that evaluate the impact of graphical features on taskperformance. Linear diagrams represent sets using straight line segments, with line overlaps correspondingto set intersections. This study builds on recent empirical research, which establishes that linear diagramscan be superior to prominent set visualization techniques, namely Euler and Venn diagrams. We addressthe problem of how to best visualize overlapping sets using linear diagrams. To solve the problem, weinvestigate which graphical features of linear diagrams significantly impact user task performance. Tothis end, we conducted seven crowdsourced empirical studies involving a total of 1,760 participants. Thesestudies allowed us to identify the following design principles, which significantly aid task performance: usea minimal number of line segments, use guidelines where overlaps start and end, and draw lines that arethin as opposed to thick bars. We also evaluated the following graphical properties that did not significantlyimpact task performance: color, orientation, and set order. The results are brought to life through a freelyavailable software implementation that automatically draws linear diagrams with user-controlled graphicalchoices. An important consequence of our research is that users are now able to create effective visualizationsof sets automatically, thus improving human–computer interaction

Narratiivin variaatio: mediakertomusten visualisointi

The media plays an increasingly large role in shaping social reality, and even small shifts in its narrative content or tone can have widespread repercussions in the public’s perception of past and present phenomena. Being able to track changes in media coverage over time, particularly visually, could have many conceivable applications and offer the potential for aiding social change in journalism. This case study explores how data visualization could be used to examine differences in media narrative patterns over time and across publications. The findings indicate that while there are many existing means of visualizing patterns in such narrative data on a timeline axis, few if any address the aspect of co-occurrence of variables. Comparing co-occurrence chronologically, particularly when applied to word and topic choices in media coverage, can shed more light on currents in public opinion than simply counting the occurrence of terms independently. Furthermore, the findings suggest that visualizing such patterns in this case could be best accomplished using a form of set visualization, specifically a simplified vertical version of linear diagrams repeated horizontally across parallel timeline axes. This case study also outlines the methods, ethical considerations, and examples of employing such a visualization prototype using a sample dataset of full text news articles.Medialla on yhä suurempi rooli yhteiskunnan todellisuuden tuottamisessa, ja jopa pienet muutokset sisällössä voivat laajalti muokata yleisön käsitystä menneistä ja nykyisistä ilmiöistä. Mediasisältöjen muutosten seuranta, erityisesti visuaalisesti, soveltuisi moneen tarkoitukseen ja voisi edistää vastuullisen journalismin kehitystä ja käyttöä yhteiskunnassa. Tässä tapaustutkimuksessa selvitetään, miten tiedon visualisointia voitaisiin käyttää tutkimaan eroja mediakertomuksissa ajan myötä eri julkaisuissa. Tulokset osoittavat, että vaikka olemassa olevia keinoja vastaavan tiedon visualisointiin löytyy, yksikään ei tuo esille muuttujien samanaikaisuuden näkökulmaa. Samanaikaisuuden vertailu kronologisesti, erityisesti sana- ja aihevalintoihin sovellettuna mediasisällön osalta, voi paremmin valaista yleisen mielipiteen virtoja kuin yksittäisten sanavalintojen laskeminen. Lisäksi havainnot viittaavat siihen, että tällaisten mallien visualisointi voitaisiin parhaiten toteuttaa käyttämällä joukko-opin visualisointeja, erityisesti lineaaristen kaavioiden yksinkertaistettua vertikaalista versiota rinnakkaisilla aikajana-akseleilla. Tässä tapaustutkimuksessa esitetään myös menetelmät, eettiset näkökulmat ja esimerkit tällaisen visualisointiprototyypin tuotosta ja käytöstä uutisartikkelidataa hyödyntäen

Observing the Truth: Diagrams, Sets and Free Rides

There are many dierent notations that can de ne relationships between sets, some of which are diagrammatic and others symbolic. Even when a notation is selected, there are choices to be made between semantically equivalent, yet syntactically dierent, statements. Syntactic choices include variations in both abstract syntax and concrete syntax where graphical and topological properties can dier. Whilst it is clearly important to understand the relative bene ts of choices in all senses, the focus here is on the choice of notation and, within that, abstract syntax choices

MetroSets: Visualizing Sets as Metro Maps

We propose MetroSets, a new, flexible online tool for visualizing set systems using the metro map metaphor. We model a given set system as a hypergraph $\mathcal{H} = (V, \mathcal{S})$, consisting of a set $V$ of vertices and a set $\mathcal{S}$, which contains subsets of $V$ called hyperedges. Our system then computes a metro map representation of $\mathcal{H}$, where each hyperedge $E$ in $\mathcal{S}$ corresponds to a metro line and each vertex corresponds to a metro station. Vertices that appear in two or more hyperedges are drawn as interchanges in the metro map, connecting the different sets. MetroSets is based on a modular 4-step pipeline which constructs and optimizes a path-based hypergraph support, which is then drawn and schematized using metro map layout algorithms. We propose and implement multiple algorithms for each step of the MetroSet pipeline and provide a functional prototype with \new{easy-to-use preset configurations.} % many real-world datasets. Furthermore, \new{using several real-world datasets}, we perform an extensive quantitative evaluation of the impact of different pipeline stages on desirable properties of the generated maps, such as octolinearity, monotonicity, and edge uniformity.Comment: 19 pages; accepted for IEEE INFOVIS 2020; for associated live system, see http://metrosets.ac.tuwien.ac.a

Evaluating graphical manipulations in automatically laid out LineSets

This paper presents an empirical study to determine whether alterations to graphical features (colour and size) of automatically generated LineSets improve task performance. LineSets are used to visualise sets and networks. The increasingly common nature of such data suggests that having effective visualisations is important. Unlike many approaches to set and network visualisation, which often use concave or convex shapes to represent sets alongside graphs, LineSets use lines overlaid on a graph. LineSets have been shown to be advantageous over shape-based approaches. However, the graphical properties of LineSets have not been fully explored. Our results suggest that automatically drawn LineSets can be significantly improved for certain tasks through the considered use of colour alongside size variations applied to their graphical elements. In particular, we show that perceptually distinguishable colours, lines of varying width, and nodes of varying diameter lead to improved task performance in automatically laid-out LineSets

Evaluating the Impact of Clutter in Linear Diagrams

Linear diagrams are an effective way of visualizing sets and their relationships. Sets are visualized by a collection of straight line segments and the ways in which the lines overlap indicate subset and disjointness relationships. As with many visualization methods, linear diagrams can become cluttered. In previous research, we established a clutter measure for linear diagrams that was empirically shown to cor- relate with perceived clutter. The aim of this paper is to determine the impact of linear diagram clutter on user task performance. An empirical study was conducted with three levels of clutter. Surprisingly, we found that diagrams with a medium level of clutter had signi cantly slower task performance than low and high cluttered diagrams. Moreover, we found no signi cant performance difference between the low and high clutter. We concluded that clutter affects the interpretation of linear diagrams. A future research goal is to establish methods for controlling the level of clutter in linear diagrams, such as using multiple diagrams instead of a single diagram, when visualizing sets

Evaluating Free Rides and Observational Advantages in Set Visualizations

Abstract: Free rides and observational advantages occur in visualizations when they reveal facts that must be inferred from an alternative representation. Understanding whether these concepts correspond to cognitive advantages is important: do they facilitate information extraction, saving the ‘deductive cost’ of making inferences? This paper presents the first evaluations of free rides and observational advantages in visualizations of sets compared to text. We found that, for Euler and linear diagrams, free rides and observational advantages yielded significant improvements in task performance. For Venn diagrams, whilst their observational advantages yielded significant performance benefits over text, this was not universally true for free rides. The consequences are two-fold: more research is needed to establish when free rides are beneficial, and the results suggest that observational advantages better explain the cognitive advantages of diagrams over text. A take-away message is that visualizations with observational advantages are likely to be cognitively advantageous over competing representations