I'm new to the idea of EA, and interested in pursuing it further. I'm finding that I have a hard time buying the argument of using expected value to make a decision, when I don't have a large number of decisions I get to make. Expected value works because it "averages out" over the long term. I'm especially concerned about the recommendations by GiveWell on deworming. I am not a rich person, and I want to be able to make an impact if I can. Nothing in life is a certainty. That said, putting a large portion of the $ that I can contribute to something that has a high probability of not succeeding means that there is a high probability that my contribution will make no difference whatsoever. If I put money into a large number of causes, each of which has that profile, and if they are independent of each other, I accept that expected value kicks in. But in the case where I only get to make a contribution to a very limited number of causes, I don't see that expected value is the right philosophy. Can anyone help clarify?