This is a followup to my original post about the timelines on the Family Trees at Ancestry.com.

The "ages" as shown in the timeline are not pulled from the census, but rather are pulled from the year of birth listed in the timeline. I concluded, incorrectly, that since the year of birth was approximate that ages shown in the timeline would also be shown as approximate.
The image here with the birth empty does not have any ages shown, which seems to indicate the age is pulled from the birth.

The second image with the year of birth, listed as approximate, shows ages.

When I create timelines based on approximate years of birth, I include "about" in front of every age because the ages at specific points in time are not based upon a precise date of birth.

If there was one improvement I could suggest, it would be to include "about" before ages that are calculated from an approximate year of birth.

That said, Ancestry.com is not drawing the ages from the census enumeration. It was incorrect when I indicated they were. The problem is that nowhere on the screen does it indicate from where the ages were inferred. Had I had other records for Abraham, the ages would have been shown for every event.

All of which points to the importance of citation. I'm not certain Ancestry.com really has room to cite sources in these timelines and I'm not certain people really want that. But I bet it wouldn't be too hard to insert an asterisk after the age indicating it was inferred from the year of birth. And that might even encourage more genealogists to be concerned about citation and that wouldn't be a bad thing.