Experiments can fail if they are executed or planned improperly. If both the control and the experimental group are given sugar pills, for example, or the equipment fails in a shower of sparks, the experiment has provided no evidence by which one can update. It is a small quibble, and probably not what the quote meant to illustrate (I'm guessing that the experiment provided evidence which downgraded the probability of the hypothesis), but something to note nonetheless: experiments are not magic knowledge-providers.
Experiments can fail if they are executed or planned improperly. If both the control and the experimental group are given sugar pills, for example, or the equipment fails in a shower of sparks, the experiment has provided no evidence by which one can update.
I think Ferguson would call those "results," and from those you would have learned about performing experiments, not about the original hypothesis you were interested in.
Another month has passed and here is a new rationality quotes thread. The usual rules are: