This experiment is not about a law of physics; it is about the instrument itself. You measure the diameter of a metal rod first with a ruler and then with a vernier caliper, and watch the two tools be wrong in two completely different ways.
What makes this one different
The other experiments chase a number like g or k. This one chases the thing sitting underneath all of them: when you write “±0.01”, what exactly have you claimed?
The more measurements you take, the smaller the error on the mean becomes — but the distance between your answer and the truth does not necessarily shrink with it. The caliper is about twenty times more precise than the ruler, and that is precisely what makes its zero error dangerous: it hands you a very confident number that can be entirely wrong. Precision and accuracy are not the same thing.
There is also a “check the instrument zero” button. Press it before you measure and you can find the zero error and subtract it — the boring first step of every real lab session. The reveal box tells you at the end whether you bothered.