Alright, since you could not verify the Earth being round without knowing my belief structure...

2+2 = 4

You don't know my belief structure. Is it true?

I'm not asking you if you know that off the top of your head, I'm asking if you could go out and check to see if it's actually true!

That's what I mean by evaluating a claim - can you verify it? I'm sorry, but it's asinine to say that you cannot verify it because you don't know how I came to the conclusion. You seem to be arguing something about sharing my language as maintaining your point. I'm past that. If you understand the claim, you can test it.

If it is divergent, then this

Let me distill this and see if you follow: We need to know what a claim is actually claiming - that can depend on context. Given that you do know what a claim is claiming, its veracity does not depend on context, nor the belief structure of the person behind the claim.

is what I meant. To provide an example, (which can quite often help in these situations):

I claim that the earth is approximately round.

You don't need to know how I came to that conclusion in order to evaluate my claim.

Had I claimed something a bit more complex, maybe related to the society that I currently live in, then you would probably need to know something about my society in order to see if my claim was correct. But you actually wouldn't need to know how I came to the conclusion - you just need to know what I'm talking about.

Let me distill this and see if you follow:

We need to know what a claim is actually claiming - that can depend on context.

Given that you do know what a claim is claiming, its veracity does not depend on context, nor the belief structure of the person behind the claim.

The meaning of a claim can, in fact, change based on the context. Moreover, the truth of a claim may change with time (for instance, the claim "Elvis is alive" was at one point true and is now false. Also note that, in the context of me making up a simple example of a claim to demonstrate my point, the meaning is likely referring to the famous performer Elvis Presley rather than any person named Elvis.

Thus we can see how there are a few things that we need to keep in mind when we address a claim, much as you have said above. However, the truth of the claim, given that you understand the meaning and you are evaluating it at a particular time, does not depend on the belief structure.

The reason I said "we shouldn't really care how someone formed their beliefs" is because the words that followed are "when evaluating the veracity of a claim," i.e. whether or not it is accurate. This is entirely independent of the person's reasons for making the claim.

I think we should also separate the subjects of the psychology behind when this might happen and whether or not we are using scales.

It may indeed be the case that people are bad accountants (although I rarely find myself assuming these implied things, and further if I find that my assumptions are wrong I adjust accordingly), but this doesn't change the fact that we are adding +/- points (much like you're keeping score/weighing the two alternatives).

Assuming a perfectly rational mind was approaching the proposition of reactor A vs reactor B (and we can even do reactor C...), then the way it would decide which proposition is best is by tallying the pros/cons to each proposition. Of course, in reality we are not perfectly rational and moreover different people assign different point-values to different categories. But it is still a scale.

I would call coming to conclusions like this a shortcoming of our rational thinking, rather than the weighing of benefits and costs to a decision. What HalFinney said is completely right, in that we very often have to pick alternatives as a package, and in doing so we are forced to weigh factors for and against a proposition.

Personally, I wouldn't have "factually incorrectly" jumped to the conclusion you stated here (especially if the converse is stated explicitly as you did here), and I think this is a diversion to the point that you are necessarily (and rationally) weighing between two alternatives in this particular example that you chose.

That being said, I wholeheartedly agree with the idea of evaluating claims based on their merits rather than the people who propose them - that's the rational way to do things - and rational people would indeed keep a notebook even if, in the end, it was going to end up on a scale (or a decision matrix).

Sorry for following you around so much (I just read this article since you linked to it in our other discussion)

There are two main points, both of which have largely been said or touched on already in your discussion here:

1) When discussing an event or something "playing out," we are talking about a cause and effect. Despite the fact that many things in life have many factors, there are always positive causes for things, which may or may not have counteracting factors. When we want to describe an effect of interest, then the simplest way to do it is to list the cause(s).

2) There are several factors (that I've thought of off the top of my head) that play into what kinds of points you provide when you are presenting a cause/effect relationship:

The first (which DavidAgain mentioned somewhat already) is whether you are trying to describe something that has happened or something that will happen. When we don't know what the outcome of something will be, we must exhaustively weigh all of the factors that we know of and their possible interactions in order to come to the best conclusion about the result. (Really there are two variations on this: what action should be taken vs. what will happen given the current state of the world, but the concept holds in each). If, however, something has already happened, it is reasonable to focus on the causes, A) because we know that they ended up "winning" and B) because there may or may not be negating factors involved in the first place.

If I say something along the lines of "I went swimming today because I was hot," it is not dishonest/biased to refrain from mentioning the fact that I weighed this course of action against several reasons not to do so - the important, primary causation was relayed in the statement and satisfies most people to the extent that they care about the factors involved.

Another factor that might be relevant is how contentious the subject is; even if you are debating something in the past, such as why X happened (or offering a proposal for why X happened), if the conclusion to be drawn is not readily agreed upon then it is prudent to first make sure that all of the relevant facts are presented. On the other hand, if you're trying to teach/explain why something happened in a non-contentious atmosphere, then it may be reasonable to omit facts that are unimportant to maintain coherency and avoid getting bogged down in clutter that doesn't matter to the overarching point. Which category Diamond's book falls under is a bit unclear, but I still am not convinced that it was biased to provide causes without enumerating all of the pros/cons, given that you trust him to the extent that he is telling the truth when we says that the Fertile Crescent was a highly, if not the most advantageous locations for the start of agriculture.

I am on the fence as to whether or not Jared Diamond was slightly biased in this case, but I think it depends on whether you look at his book from the perspective of a comprehensive argument/claim or a proposition of a different mechanism behind how things ended up the way they did which may or may not account for all of history in its complex entirety.

Anyway, I think trying to infer bias based on the presence of pros/cons is a difficult subject. I wouldn't go claiming someone is biased towards something for only presenting a positive message necessarily, even though this is often the case. Even in the example with the teams coming very close to a tie, the response to "why did they win" may have been correct, in that they had all of those factors in their favor and that those were enough to win (barely). I agree that in this case the guy was biased, but on the other hand they didn't ask him "what factors were involved and why did they favor Man City (somewhat)?"

That's about all I'll say for one response - I have a bad tendency of rambling on when I've already made the points that I really wanted to make.

(by the way DavidAgain I loved the way you said the things I was thinking with each consecutive response - I was vicariously participating in the discussion through your comments!)

I agree that it is largely off-topic and don't feel like discussing it further here - I would like to point out that the principle of indifference specifies that your list of possibilities must be mutually exclusive and exhaustive. In practice, when dealing with multifaceted things such as claims about the effects of changing the minimum wage, an exhaustive list of possible outcomes would result in an assignment of an arbitrarily small probability according to the principle of indifference. The end effect is that it's a meaningless assignment and you may as well ignore it.

I'm making a separate reply for the betting thing, only to try to keep the two conversations clean/simple.

Let's muddle through it: If I have a box containing an unknown (to you) number of gumballs and I claim that there are an odd number of gumballs, you would actually be quite reasonable in assigning a 50% chance to my claim being true.

If I claim that the gumballs in the box are blue, would you say there is a 50% chance of my claim being true?

What if I claimed that I ate pizza last night?

You might have a certain level of confidence in my accuracy and my reliability as a person to not lie to you; and, if someone was taking bets, you would probably bet on how likely I am to tell the truth, rather than assuming there was a 50% chance that I ate pizza last night.

If you you then notice that my friend, who was with me last night, claims that I in fact ate pasta, then you have to weigh their reliability against mine, and more importantly now you have to start looking for reasons that we came to different conclusions about the same dinner. And finally, you have to weigh the effort it takes to vet our claims against how much you really care what I ate last night.

So, assuming you are rational, would you bet 50/50 that I ate pizza? Or would you just say "I don't know" and refuse to bet in the first place?

There's a whole bunch of information out there - literally more than any one person could/cares to know - and we simply don't have the time (or often the background) to fully understand certain fields and more importantly to evaluate which claims are true and which aren't. In other words, reality is objective and claims should be evaluated based on their evidence, not the person who proposes them.

It would seem to me that these claims aren't consistent. I agree with the first claim, not with the second. It's true that experts' claims are objectively and directly verifiable, but lots of the time checking that direct evidence is not an optimal use of our time. Instead we're better off deferring to experts (which we actually also do, as you say, on a massive scale).

I think we are in agreement but my second statement didn't have the caveats it should have; I doubt you would disagree with the first half, that reality is objective. You disagreed with the second half, that claims should be evaluated based on evidence -- not because it's a false statement, but rather that, in practice, we cannot reasonably be expected to do this for every claim we encounter. I agree. The unstated caveat is that we should trust the experts until there is a reason to think that their claims are poorly founded, i.e. they have demonstrated bias in their work or there is a lack of consensus among experts in a similar field.

I guess the main thing I am trying to say that directly ties into your post is that we shouldn't really care how someone formed their beliefs when evaluating the veracity of a claim; when we should care is:

I don't agree with that. We use others' statements as a source of evidence on a massive scale (i.e. we defer to them. Indeed, experiments show that we do this automatically. But if these statements express beliefs that were produced by unreliable processes - e.g. bias - then that's clearly not a good strategy. Hence we should care very much of whether someone is biased when evaluating the veracity of many claims, for that reason.

Hold on now, you did read my bullets right? When we should care is:

• When we suspect that a bias may have lead to a false reporting of real information (in which case we would want independent, unbiased research/reporting)

Notice that I actually did say suspicion of bias is an exception to the "not caring" statement. In other words, unless we have a reason to suspect a bias, (and/or the second bullet) then we probably won't care. There can be other ways of bad conclusions being drawn; the reason I mention bias is because it is systematic. If we see a trend of a particular person systematically coming to poor conclusions, whatever their reason, then our confidence in their input would fall. On the other hand, experts are human and can make mistakes as well - we should not dismiss someone for being wrong once but for being systematically wrong and unwilling to fix the problem. If we really care about high confidence in something, for instance in the cases where the truth of the claim is important to a lot of people and we want to avoid being mislead if there are a few biased opinions, we seek the consensus.

Now, can we get the consensus all of the time? Unfortunately not. Not even most of the time. So what's our next line of defense? Well, one of them is journalistic integrity; frankly I don't even want to go there, but if done properly there are people whose job it is to sort through these very things - but really let's not go there for now. The last line of defense is yourself and the actual work of checking on things yourself.

If a claim is important enough for you to really care whether or not it's accurate, then you have to be willing to do a little bit of digging yourself. Now I realize that the entire point of this post was to avoid just that thing and to have computers do it automagically; but really, if it is important enough for you to check on it yourself, rather than just trusting your regular sources of information, then would you be willing not to check just because a program said that this guy was unbiased?

That might be a bit of an unfair characterization of what you're discussing, but there is a distinction to be made between using online behavior to measure/understand the general population's belief structure and to check for bias in expert opinions.

I think the idea of understanding the population's belief structures would still be extremely useful in it's own right though, per my second bullet in the exceptions to the "don't care" statement - particularly if someone wants to change a lot of people's minds about something. If you have a campaign (be it political or social), then understanding how people have structured their beliefs would give you a road map for how best to go about changing them in the way you want. To some extent, this is how it's already been done historically, but it was not done via raw data analysis.