Mark Goodacre's blog has another great post pointing out another fatal flaw of the program's statistics. A statistician has written pointing out that the simple statistical test that was performed was one of conditional probability, i.e. the probability of an event on the condition that another event has occurred. In other words, the test is only valid on the condition that Jesus had a family tomb in Jerusalem and that this tomb was among the 1,000 discovered so far! The author Joe D'Mello states that the results have been touted by the program as
There is only a 1 in 600 chance that this is NOT the Jesus family tomb.” OR, equivalently, “There is a 599 in 600 chance that this IS the Jesus family tomb.
When in reality the probability is closer to:
If the Jesus family did indeed have a family tomb (that was among the 1,000 found), then there is a 599 in 600 chance that this particular tomb found is indeed that of the Jesus family
In other words, this computation starts from the assumption that Jesus' tomb would have been in the sample. D'Mello says: "We know from classical probability theory that P(B) * P(A|B) = P(A and B) (* stands for multiplication) Now, P(A and B) is the probability that the Jesus family had a family tomb AND that the tomb discovered is that of the Jesus family. Note that the media are taking P(A|B) (Feuerverger’s 599/600 number) and wording it in a manner that makes it appear to the general public that it is in fact P(A and B). This is a fallacy and an out right deception!" If one tries to factor in the odds that Jesus' family would have had a tomb to begin with (which was more common among the wealthy), and if one very generously assumes that there is a 1 in 10 chance of this, the odds immediately drop from 99.8% (i.e. 599 out of 600) to less than 10% right off the bat. And one would still need to factor in the odds that this tomb would have been located in Jerusalem (rather than Galilee or elsewhere) and would have been among the 1,000 uncovered already. And this does not even address the other crucial questions, such as why "Mary Magdalene" would be included in the control to begin with (since there is zero evidence that she was part of Jesus' family), how the Mariamene could be considered a "hit" for "Mary Magdalene," the other non-hits that are glossed over, the papponymic naming practices of the Jews which eliminated the possibility of X-bar-X names, and the fact that this tomb was in use for several generations -- suggesting that the named individuals belonged to different generations.