Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 08 - Aufgabe 1 - Theme River

Quotation

The ThemeRiver visualization depicts thematic variations over time within a large collection of documents. The thematic changes are shown in the context of a time line and corresponding external events. The focus on temporal thematic change within a context framework allows a user to discern patterns that suggest relationships or trends. For example, the sudden change of thematic strength following an external event may indicate a causal relationship. Such patterns are not readily accessible in other visualizations of the data. We use a river metaphor to convey several key notions. The document collection's time line, selected thematic content, and thematic strength are indicated by the river's directed flow, composition, and changing width, respectively. The directed flow from left to right is interpreted as movement through time and the horizontal distance between two points on the river defines a time interval. At any point in time, the vertical distance, or width, of the river indicates the collective strength of the selected themes. Colored "currents" flowing within the river represent individual themes. A current's vertical width narrows or broadens to indicate decreases or increases in the strength of the individual theme.

[Havre et al., 2002]

Pros

• contextual information
• zooming to specific and/or exact period of time
• changes in themes are good visualizable
• easy to interpret
• its a time slice and not summarized with bars like in an histogram
• it provides an overview
• easy to use
• switch particular theme labels on and off

Contras

• not possible to filter out exakt data
• color blind people may have problems reading the ThemeRiver if it only is presented in colors and without texture

Usage

The Theme River can be used for example for

• political actions
  • survival rate of soldiers in different positions
• economic actions
  • waterlevel in different countries
• military actions
• international events
• ...

References

• [Havre et al., 2002] Susan Havre, IEEE Computer Society, ThemeRiver: Visualizing Thematic CHanges in Large Document Collections, Vol.8. No.1., January-March 2002 http://www.cg.tuwien.ac.at/courses/InfoVis/HallOfFame/2004/05_ThemeRiver/papers/ThemeRiverIEEE2002.pdf
• http://www.cg.tuwien.ac.at/courses/InfoVis/HallOfFame/2004/05_ThemeRiver/