Also, on the Petrov day market, let’s suppose the question had been “What % of Petrov Day will elapse before someone uses the big red button to take down Less Wrong’s frontpage for the rest of the day?” (“for the rest of the day” is the only change.) I would consider this reasonably unambiguous—if LW decides to bring the page back up because it was a “mistake” then it shouldn’t resolve yet. But I suspect that people would have bet on that nearly the same as the actual question, and your hypothetical user who saw the site was down at 10% would also have been burned. It’s still better to avoid the ambiguity, I agree, but the problem of traders being burned by details is still there even if you avoid ambiguity in the details.
This sort of thing happens in the financial markets too. I’m thinking of all the games that happen over credit-default-swaps, for example. It would be nice if we could magically reduce complexity to reduce the impact of these sorts of issues, but it’s a risk market participants are taking on by trading in the markets, and I think the value the markets provide is still clearly worth it (or else people wouldn’t be willing to trade in them)!
I agree that ambiguity is bad, and most Manifold markets are probably too imprecise and ambiguous. My usual style is trying to be fairly precise in the forecasting questions I write, and I definitely second your recommendations!
However, I want to point out that the problem isn’t just ambiguity, but really complexity. The more you try to nail down the resolution criteria, the more likely it becomes for there to be a serious mismatch between the top-line summary of the question (the question that you are actually interested in answering) and the detailed decision tree used to resolve it.
Here’s a great example with a real-money, CFTC-regulated prediction market “Will student loan debt be forgiven?” on Kalshi. The rules were as unambiguous as possible up-front, specifying what would count as “broad-based debt relief” and things like that—things that people would reasonably think are important details to check. Unfortunately, it turned out that there was a huge detail in the resolution criteria that the market missed—the resolution rules required that the forgiveness be done via Executive Order or law. And in this case, the debt relief was clearly done but it wasn’t done by law or executive order. So lots of traders lost lots of real money, and the prediction market clearly failed at its job. Link to the market: https://kalshi.com/events/SDEBT/markets/SDEBT-23JAN01. (Note: the page has been updated after the fact to highlight this issue.)
This is to highlight the point that writing unambiguous resolution criteria that also match the top-line summary question is really really hard! It’s not uncommon on Metaculus for there to be a fairly clear subjective answer that differs from the actual resolution because of some issue that most people agree is a mere technicality. So I think that trying to disambiguate is good, but being willing to step back from technicalities is also potentially good. There are advantages to both approaches. I agree with you that the average market on Manifold is way too underspecified and ambiguous, but if you require Metaculus levels of precision then many people wouldn’t be willing to spend the effort to ask the questions at all, and that is also a loss.