youngalexander

Quite! Another point which you are demonstrating is that probability is tricky for lay persons because one must be very precise in formulating the question. In this case any sequence of 40 P(x) = 0.5 independent events would have an equal probability.

It often occurs that the formulation is misunderstood and thus the 'correct' result is surprising. It is this ability to hone in upon precise questions by examining all the pros & cons, that provides a core value of the Baysian approach, not some supposed mathmatical accuracy.

johno

I vaguely remember William Lane Craig 'proving' that the empty tomb had some sort of religious significance by Bayesian arguments, such obvious tosh that I didn't bother with the details, and can't remember where I read it. Also I was present at a lecture in the Divinity School of Aberdeen University where some fraud of a professor of theology from the University of Oxford 'proved' using Bayes's theorem that divine creation was more probable than evolution. The 'proof' was provided on the blackboard in a flurry of ill-drawn symbols to an audience made up of mathematically deprived divinity students. The details are now vague, but I remember that the proof was based on the assumption that since the alternatives were god or evolution the prior probability of each was p = 0.5

tanya

Apologies for my gross stupidity.

Here's why I erred (not a gender related deficient education, don't blame the democrats)

singular.........................plural........... .........NOT

woody plant.............woody plants..............woody's plants

oak plank.................oak planks..................oaks planks

botanical garden........botanical gardens........botanicals gardens

Papyrus baskets, or papyri baskets? baskets made of papyrus, or baskets made of papyri? If "people harvest papyrus", does that suggest that they harvest one single plant, or, can papyrus also represent the plural?

Perhaps papyrus, when used as a mat, basket, or fish trap, can represent either singular or plural, but when referring to a document, must refer exclusively to only a single specimen? So, papyri for multiple documents, but papyrus, not papyri, for multiple mats or fish traps (fishes traps?).....oh, yeah. got it. Thank you Legionaire, good job.

let's see, oak seedlings, no. should be oaks seedlings, because I am planting multiple species...hmm. not a transparent algorithm. What if they include both red oak and white oak seedlings? Would we then write oaks seedlings? I would not. I would still write oak seedlings, even with multiple plants, and multiple species in the same planting basket(s).

papyrus document: a document made from papyrus. It is not a document made from papyri. Papyrus documents: multiple documents made from papyrus. These documents are not made from papyri.

*******************************************

Almost.

The question is, what information must be available to any investigator seeking to employ Bayes' theorem, in any discipline? Then, the related question arises: Is that required information available to those engaged in a study of the origins of earliest Christianity?

I contend that since this required information is not available, it does not matter which particular issue one seeks to scrutinize using Bayes' theorem. I only chose Mark 1:1 to illustrate why one cannot invoke Bayes' theorem, willy nilly. Lacking the necessary required information, there is no basis for claiming a substantive difference between use of Bayes' theorem, and not using this mathematical massage.

mountainman

The information about Christian origins sourced from various items of ancient historical evidence is largely hypothetical in nature. Jesus himself is hypothetical. It can be no other way.

Bayes theorem uses these hypotheses about the evidence as inputs. We have seen demonstrations of the GIGO nature of Bayes when people try and prove the resurrection happened, and other claims, using Bayes.


Bayes theorem is useful in assessing the comparitive probability of prior information by comparing it to common sense. For example, what are the statistics for people walking on water, ascending through cloudbanks, and rising from the dead?

Bayes theorem was used by Carrier (link above) to demonstrate the illogical nature of certain key criteria (e.g. the "Criterion of Embarrassement") that apologists and others had been using to pull the wool over the eyes of themselves and their audience for centuries. In this sense, it has already been shown to be useful.

I have no idea of Carrier's agenda. The hypothesis that Jesus was historical, and its antithesis that he was not, may be tested against each other using Bayes. I am assuming Carrier is to test and compare these two antithetical hypotheses using Bayes.

LegionOnomaMoi

Not knowing something is not stupidity. When one studies linguistics and languages, these things tend to get implanted in one's brain. So even though "schemas" and "formulas" are both commonly accepted words, they still bother me.
It depends on how you are using the word. As a material used in construction, for example, "oak" can be used as a "mass noun" rather than a "count noun" and thus one can speak of oak planks. It's basically an adjectival use, and most grammarians would simply say that it is an adjective. The way to test usage here is to drop out what follows the noun/adjective in question. Thus, while I can say "the ship was built out of oak" and not use the plural, and I can't say "the ship was built out of oaks," I cannot say "we study ancient papyrus" (unless I mean the plant). I have to say "we study ancient papyri." The difference between oak and papyrus here is that while "oak planks" requires "planks" one need not say "papyri documents" rather than just "papyri." In English, papyrus almost always refers to writings on this material, rather than the material alone. Hence we find authors referring to "this papyrus fragment" or stating something about "papyri from the 3rd century."


This is exactly what I mean. Take a look at how papyri is used (look up, for example, oxyrhynchus papyri or new testament papyri). A "papyrus document" is either redundant (as, e.g., "studies of ancient papyri" means "studies of ancient writings on papyrus made from a papyrus plant), or you are using it for something like emphasis to (perhaps) make clear you are distinguishing papyri documents from codices.


Until you understand Bayes' theorem and how it is used, contending anything is just a waste of time. I provided you a link to Carrier's explanation and usage of the theorem. Again, if you want to conclude that his methodology is flawed, the only way to validly do so is by understanding it. If you read his explanation and demonstration, and you can point to specific problems in this usage, then do so. Otherwise (again), you are doing the equivalent of demanding that someone provide you the day, month, and year a particular a particular paprus fragment dates from.

outhouse

Not only that its really not 50/50 anyway, the test have been done showing its not equal odds due to the weight placement within the penny

aa5874

Your first error is that you claimed Using COMMON SENSE, We would expect the results to tend to show a 50% probability but It is hardly likely, by using common sense, that people would say that we would expect the very identical sequence or all heads or all tails.

I have access to the results of coin tosses where heads or tails is called 20 times or more by over 30 persons and NONE of them show that all calls were 100% correct or 100% wrong.

LegionOnomaMoi

I notice you conveniently quoted a different post than the one you responded to. It wasn't an error, but it may not have been clear that I meant "expect a coin toss that tends to look something like this." Which is why I later phrased the question in a much clearer and to the point manner:
It was this post that you responded to:
What I said was true, and yet probability has meaning (and as history is about determining what "most likely" happened, probability absolutely has significance in historiography, whether informal or formal). But rather than admit that you were quite wrong (and most people do get questions like this wrong, which was one of my points concerning the usefulness of Bayes'), you went back to a different post which was less clear and tried to use that to claim I made an error.


The question I asked (and answered) which you responded to by saying that "if what I say is true" then "probability has no meaning" was quite specific. I gave two specific sequences representing the results from two series of 40 coin tosses, and asked which is more likely. I then said the probability of both is equal. This is true (of course, I'm assuming a "fair coin" but I would have thought "common sense" made at least that part obvious).

I have no idea what this has to do with anything. Again, I gave to specific sequences of the results of two series of coin tosses. When I said the probability of both was exactly equal, you responded by saying that if I was right then probability has no maining. Nothing you've said here explains that comment.

aa5874

Your claim is absolutely wrong. The probabilty of .5 is NOT expected to produce 40 consecutive tails, it is expected to prodce RANDOM amounts of heads and tails that APPROACHES the probability of .5.

blastula

aa5874, you are only proving his point.