After making extensive use of my Notebooks I have noticed that a "test" can comprise only one question. Would it not be a more accurate reflection of users' efforts to base the Leaderboard on the number of questions answered, rather than tests completed? This is of course a minor criticism, but I thought it worth raising as I find the Leaderboard ranking an added incentive to keep up my work rate, but at the same time I don't see any value in completing lots of mini tests. Many thanks for a very useful service.