One feature we enabled with the Timecard device was the ability to add reference material. Using Wikipedia, the author of the timeline can search for contextual material (details about world events, for example) to add as a complement to the more personal content. On my grandfather’s timeline, I added references to events he may have been involved in, such as the Battle of Britain (a famous skirmish involving the Royal Air Force), so I had a sense of broader occurrences that may have affected his life directly.