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A tale of two tools (NVSS and VisLink)

Shreya Rawal

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Network Visualization by Semantic Substrates

(Ben Shneiderman and Aleks Aris)

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Some problems in node-link diagram

Node OcclusionEdge CrossingEdge Tunneling under nodes

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How to define semantic substrates?

Group nodes into regions According to one attribute

Categorical, ordinal, etc.

In each region: Place nodes according to the

remaining attribute(s)

Give users the control of link visibility

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DatasetCourt Cases (Nodes)

Supreme Court CasesCircuit Court Cases

Citation of one case by another (Links)Within the same court (Circuit to Circuit and so on)Within the different court (Circuit to Supreme and so on)

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Force Directed Layout36 Supreme & 13 Circuit Court decisions

368 citations on Regulatory Takings 1978-2002

Arranged in chronological order from left to right

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Force Directed Layout36 Supreme & 13 Circuit Court decisions

368 citations on Regulatory Takings 1978-2002

Arranged in chronological order from left to right

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NVSS 1.0Supreme court cases

Circuit court cases

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Filtering links by source-target

Check boxes for filtering the data

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Filtering links by time (per year)

Slider for filtering by time

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Three Regions

Links from District CourtsIndicates longevity of cases (short to long)

DistrictCircuitSupreme

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NVSS Scalability• 1280x1024• 1,122 nodes• 7,645 links

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Analysis of Paraiso Manifesto using NVSS

Towers on the Island

Edges joining a call of specific duration to the corresponding tower

Calls arranged by duration anddays

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Analysis of social network: Call Analysis for 1st Day

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Analysis of social network: Comparison of long vs.short

duration calls

Short Duration Call Long Duration Call

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VisLink: Revealing Relationships Amongst

Visualizations(Christopher Collins and Sheelagh

Carpendale)

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VisLink

A method by which visualizations and the relationships between them can be interactively explored.

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Compare multiple visualizations

Using different datasets and different visualization techniques

Same dataset but different visualizations

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Theory behind VisLink (1)

VisLink: 3D space within which any number of 2D semi-transparent visualization planes are positioned.

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Theory Behind VisLink (2)

Two individual visualizations

Required Visualization

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Visualization of Lexical Data

Radial hyponymy graphhyponymy relationship: {lawyers, attorney} IS-A {job, occupation}

Force directed layout for similar clustering on words (alphabetically)Do some sets of synonyms contain high concentration of

orthographically (alphabetically) similar words?

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Widget Interaction: VisLink

Book Pages Rotation

Center accordion translation

Garage door rotation

Visualization planes are independently manipulated with three widgets.

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3-D Navigation

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Example

• Treemap showing occupations of the members of Congress before elections• Scatterplot of individual fundraising success• arranged alphabetically by states• party by the color of nodes• running for House or Senate by shape

• Geographic map of zipcode

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Where did the most successful fundraising journalist get elected?

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Semantic Substrate vs. VisLink

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Comparison between NVSS and VisLink (1) Similarities:

Both dealt with multiple visualizations (on the same/multiple dataset or on the subsets of the same dataset).

Both focused on large amount of data.Both used user interaction for filtering data to extract maximum information.

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Comparison between NVSS and VisLink (2)

Constraint:You cannot apply the concept of NVSS unless you have dataset which can be logically sub-divisible.

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My Project:Traces files generated by large-scale applications written in Erlang (CouchDB, Yaws, etc.).Main components of data

ProcessesProcess communication (message send and message receive)Process spawningTimestamp

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Issues!!!

Is using multiple visualization solution to deal with more amount of data?Big picture vs. Filtered Data?2D vs. 3D?

VisLink: a very effective use of 3rd dimension.

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References:Aris, A. 2006. Network Visualization by Semantic Substrates. IEEE Transactions on Visualization and Computer Graphics 12, 5 (Sep. 2006), 733-740.Carpendale, S. 2007. VisLink: Revealing Relationships Amongst Visualizations. IEEE Transactions on Visualization and Computer Graphics 13, 6 (Nov. 2007), 1192-1199.Aris, A. and Shneiderman, B. 2007. Designing semantic substrates for visual network exploration. Information Visualization 6, 4 (Dec. 2007), 281-300.Aris, A. and Vulleot, R. Visual Analysis of the Paraiso Manifesto by Symantic Substrate.http://www.cs.umd.edu/hcil/nvss/#presentations

(Last visited on March 2, 2009)

http://www.cs.toronto.edu/~ccollins/research/VisLink/flash/index.html(Last visited on March 2, 2009)