Demo: https://iDataVisualizationLab.github.io/WordStream/
Video: https://iDataVisualizationLab.github.io/WordStream/video.html
Examples: https://idatavisualizationlab.github.io/WordStream/examples.html
WordStream is a visualization technique for demonstrating the evolution of a topic over time. This is a hybrid technique from Wordle and StreamGraph, which conveys textual data with both global and local perpsectives. Global trends is described by the total stream, in which thickness represents amount of interest/concern in that specific timepoint. Local trend is retrieved from an individual stream.
Timeline is shown from left to right, in the bottom of the interface. The categories for textual data are color-encoded, for example:
- Blue for person
- Orange for location
- Green for organization
- Red for others
The importance of a word is represented by its font size and opacity. In this study, the importance of a word is its Sudden attention: a word which appear repeatedly throughout the timeline conveys less and less meaning than in its first appearance. A word's sudden attention is a function of frequency, which is big when the previous timestep has small frequency and this current timestep has high frequency.
WordStream shows the remarkable topics by emphasizing them with font size and opacity.
In Mar 2012, users can quickly see the names such as Trayvon Martin - George Zimmerman (person) and Sanford (location), regarding the Trayvon Martin shooting by George Zimmerman. The event happened in Sanford in late February 2012, but the investigation and news appear in the next month, March.
In August 2012, some remarkable terms are Todd Akin and Paul Ryan (person), with Romney-Ryan (other). Romney-Ryan is Mitt Romney and Paul Ryan, the 2012 Republican presidential ticket. Todd Akin is a representative who had controversial statement during the Senate race, and Paul Ryan is a co-sponsored with him on the bill.
In December 2012, Sandy Hook, Newtown, Lanza and NRA are the emphasized terms. This relates to Sandy Hook Elementary School shooting in Newtown, Connecticut by the shooter Adam Lanza. The shooting caused many questions of gun control legislation to NRA (National Rifle Association).
The connection can be seen clearer by the relationship between them. Turning on feature “Relationship” will show the underlying relationships of terms. Here, we consider the relationship base on co-occurrences. Mouseover a link can highlight that connection and the pair of words.
The tool allows users to customize:
- Width, height, font size and number of chosen words (top rank).
- Flow and Angle Variance are preferences for text orientation.
- Relationships: Toggle allows relationship to be displayed.
The metrics includes measurements for the importance of the word displayed. In the process of placing word, some of them are left out due to lack of space. For example, TF-IDF ratio means the rate between the words shown to all the word.