"I don't know" means "I can't predict the outcome better than a dart throwing monkey". Doctors usually know more than that.
The example I chose is a bit misleading. I am just using it to indicate the problem though. You are thinking of 'doctors' as the doctors in our culture but I was hypothesising a situation in which the field is much more primitive. It is interesting to me to see how rationality is applied to a field where data is unavailable, scarce or inconclusive.
You seem to have a lot of black and white terms like "right hypothesis", "accepting explanations as truths" and "I don't know" in your thinking.
I don't see the problem of saying 'I don't know' when the data is obviously insufficient for me to judge. I would actually consider it counter productive to give a probability in this case, as it might create the illusion that I know more than I actually do. In this sense my 'I don't know' is not a value of 0 but admitting that there is no reason to use rational jargon at all.
The terms 'right hypothesis' and 'truth' are used, in the above comment, in the context of what is considered a good enough truth in science. You are right that this can be confusing if we get into the epistemological details though I thought it was sufficient for the purpose of communicating in this thread. I can change it to 'scientific fact' and we should be ok?
Does that make sense?
After Popper science isn't about establishing truth or the right hypothesis.
I would actually consider it counter productive to give a probability in this case, as it might create the illusion that I know more than I actually do.
If you can do better than a random guess (the dart throwing monkey) than you have knowledge in the Bayesian sense.
There could be situations where you really don't know more than the dart throwing monkey and were it thus doesn't make sense to speak about probability but in most cases we know at least a little bit.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.