The goalposts are shrouded, not moving

Alice: Are there any examples of X? Bob: Here. Alice: Okay, but are there any examples of X'? Bob: Yes, here. Alice: That has feature Y, which- Bob: Dude, stop moving the goalposts. The thing is, I think in this situation, Alice often isn't moving the goalposts. Instead, she's looking for something, and not fully specifying it up-front. Maybe because she's speaking imprecisely. Maybe because she doesn't know quite what she's looking for, but does know when she sees something that that's not it. Alice: Any research showing that supplement helps? Bob: Yes, here's a trial. Alice: Anything not funded by the manufacturer? Bob: This one was funded by the NIH. Alice: Thanks, but it's n=12 and there's no control arm. Bob: ಠ_ಠ What Alice wants to know here is should she believe the supplement helps. Asking for research is a proxy for that, and the research Bob finds answers her proxy but doesn't say much about the real question. This is probably frustrating for Bob! If he doesn't know why Alice is asking, or doesn't know why the things he finds don't help her, it might look to him a lot like she's moving the goalposts / fighting a rearguard retreat against the evidence. Like she's just looking for reasons to dismiss what he's bringing up, so she doesn't have to change her mind. But it's an importantly different thing going on. If Bob thinks this kind of thing might be going on, he might ask: "okay, help me understand here what you're actually looking for? Right now I expect that if I give another example, it'll be wrong again in some way I can't predict." And if Alice notices it, she might say: "sorry, I know what this looks like - the reason I'm asking is…". Discuss