It is essentially re-wording an assumption or set of assumptions in a way that is put more like a question, or something that needs to be tested,eg.we believe this particular set of assumptions to be true, and we will know if we are right if X happens.
Predicting the unpredictable is difficult. But if I had to guess, I would say experiments are very much in.
Why? Because we need to stop building things we do not know if our customers/end-users even want. Gather that data and then decide how to move forward. Pay particular attention to slide 5, you'll see what I mean.