A sparkline is a small, simple, data-dense graphic with typographic resolution that is shown inline and in-context with relevant text.
The term was coined by Edward Tufte, and inspired by Galileo's drawings of the shape of Saturn inline with his writings about them.
Contrary to the Wikipedia definition, sparklines are not limited to graphs, graphs are simply the most common use of sparklines (and "line graph" is unfortunately somewhat implied by the word "line" in the name). Rather, sparkline includes the kinds of graphics that inspired them in the first place, e.g. see Tufte's notes about Galileo's drawings of the shape of Saturn inline with text:
The IndieWeb wiki allows the simple addition of sparklines in the form of mini-avatars along with user's names for providing quick attributions and links within the wiki. To create your own reference the following pages:
Jeremy Keith has sparklines on his personal site (since ??-??-??) indicating how frequent certain posts have been made historically. He's also documented some of his experiments with them in the past:
An example of sparklines for Journal entries, Links, Articles, and Notes on Jeremy Keith's website
There are several plugins for adding sparklines to WordPress websites including:
- Activity Sparks plugin by Greg Jackson adds some configurable functionality for adding sparklines to WordPress sites including for posts and comments as well as for tracking categories/tags.
- Sparkplug by Beau Lebens has similarity to the Activity Sparks plugin (above), but with a slightly older and different implementation.