Cyclopath is a geographic wiki and, as a wiki, one of the important things is that users be able to view changes that have been made. We have struggled with how to display this to users. This prototype is from 2009.
The Problem: Current Site
This was the current interface. The part that we were most concerned about starts in the left column with "Map shows:". The options given were Current revision, Selected revision, or Changes, and, based on which is clicked, the buttons Update, Look At, Comment, or Revert may be enabled. One of the main problems with this interface is that the terminology is not clear. This is primarily because the idea of viewing differences in a geographic area is more complex than looking at text differences and we had trouble figuring out the best wording. This interface is complex enough that most of the Cyclopath team members cannot use it correctly without trial and error.
Idea 1: Heat Map
The model for this sketch was a heat map. The idea was that the most recent revisions would be highlighted in different colors, both on the map and in the list of revisions. That way users could easily visualize where the differences occurred and whether they might be relevant to their interests.
Idea 2: Wikipedia Interface
In this interface, next to each revision are two buttons. If you select one radio button per column, you can look at the differences between those two revisions.
Idea 2: Details
This interface shows what might happen if the first two revisions were compared. You can see on the map that two points of interests are circled in green, these indicate the items that were changed in this revision. The text near the bottom of the map also informs the user of which revision she is looking at. In addition, buttons at the top of the recent changes panel allow users to quickly get back to their place on the map or look at the newest revision. (Yellow buttons indicate the option would not be available for the user.)
Idea 2: Details
In the this interface, a point on the map has been selected without a revision being selected. This would enable filtering of the revisions on the left hand panel (not filtered here) to only revisions that involve that point.
Despite work on this problem being done (by myself and others, who worked on other designs), we did not implement any fundamental design changes to the history browser, due primarily to lack of personnel.