To investigate how participants in Wikipedia allocate their time, we have created a visualization technique, the Chromogram, that can display very long textual sequences through a simple color coding scheme.

Using chromograms we found a set of characteristic editing patterns in the online encyclopedia. In addition to confirming known patterns, such as reacting to vandalism events, the visualization reveals a distinct class of organized systematic activities that help shed light on self-allocation of effort in Wikipedia. For more details about the Chromogram technique and our results, please refer to our Interact 2007 paper and our more extensive technical report.

Visualization Technique

Simply put, Chromograms map text strings to color. The first three letters of a string determine the color of its representation. The first letter determines the hue; the second letter the saturation, and the third the brightness. Saturation and brightness were both kept in a restricted range so that the hue was easily perceived. Numbers get mapped to shades of gray. As arbitrary as this approach may sound, it actually reveals a series of important patterns in the editing activity of Wikipedians. Below is a sample of the color mapping to different words/numbers:

 

 

 

With this mapping, we can display long sequences of edits on a single screen, where each edit is represented by a small colored rectangle. By placing one colored rectangle after the other (from left to right, top to bottom), a Chromogram is created that shows a person's patterns of edits.

Results Highlights

We tracked the individual edit histories of several hundred Wikipedia users. An edit history for an individual user is a sequence of timestamped edit events, where an event consists of the title of the article edited and an optional user comment. These histories can be vast, sometimes consisting of tens of thousands of edits. Some images are below, for more details, view our paper and tech report. 

Many Wikipedians engage in what we call systematic activities: that is, a sustained related sequence of edits. Some editors seem to concentrate on particular topic areas. Figure 2 (below) shows a title chromogram where the user focused on naval history. The dominant color is a purple shade that corresponds to the prefix “USS” (United States Ship) used in the names of American naval vessels. Occasional edits with a different color are evident, but exploration of the data shows that they remain on the naval theme.

In other cases, users will give themselves a task that spans the most varied set of Wikipedia articles (that are not bound by title or subject matter). Often the organizing element of such self-imposed miniproject is a list of alphabetically-ordered articles that need attention--for example, articles that need stub sorting or re-categorization. When Wikipedians edit articles in alphabetical order, their edits show up as rainbows in Chromograms. Figures 3 and 4 below show variants of rainbow editing: at the bottom of figure 3, the user starts a couple of rainbows. Figure 4 on the right shows an all-consuming rainbow image. This user is actually a robot, not a human, programmed to edit a long series of articles in alphabetical order.  

 

Gallery

(click on images for bigger screenshots)

Fig 1. Comment Chromogram of user whose edits are mostly about adding births and deaths occurrences to year articles on Wikipedia.	Fig 2. Title Chromogram where purple equals articles of US Ships (where the article title starts with "USS")
Fig 3. Title Chromogram showing a few rainbow patterns at the bottom	Fig 4. Solid rainbows appear on the editing history of this robot whose main tasks include categorizing articles
Fig 5. This user is making maps for each city in each state of the US. Pink = Wisconsin, brown = CA. Rainbows are the towns in each state in alphabetical order	Fig 6. Comment Chromogram showing the same user as in fig.5. Light green comments start with "geography" as the user mentions the maps he has added to each article of a given town