they didn't know what the result of their experiment would be. If it had come out differently, it would have sent them back to the drawing board. they hypothes

they didn't know what the result of their experiment would be. If it had come out differently, it would have sent them back to the drawing board. they hypothesized that this particular drug/hormone intervention would have a particular effect, and an experiment was needed to confirm the hypothesis. Further experiments might show that they were even wrong even about this one, and there is some other interaction going on to fully explain what's going on.