What results to display when comparing current and past data?
Working on an analytics dashboard that allows the user to select a recent date range with the option to compare that date range against a previous time period.
Now, let's say they want to see how this week compared with last week. This week, Australia was not in the top locations, but last week it was ranked 4th. Would you expect the UI to retain the current week's results in-tact and just show the changes within those results (like shown below)? Or would you somehow incorporate Australia into the layout? If the latter, any suggestions on doing so? (please disregard the math in the examples)
Intuitively, I would expect the current list of "Top Locations" to remain in place and in the same order, but simply with an additional bar showing last week's values.
In the case of no data for the previous week, as in your description of Australia, add an empty bar to be explicit about the "emptiness" of last week's data, and maybe a short bit of info describing the data, or, if you feel it flows better, as a footnote.
(Still do keep the data on the right; I just didn't mock it up. Perhaps Australia's percentage change label is where the asterisk belongs to indicate that this data has an explanation.)
Also relevant, I would recommend considering using flat ends for your bars, specifically when comparisons are necessary. The rounded ends are more difficult to see how visually significant the difference in length is.