Knickerbocker Photo (Update)

[Snowman]

Originally Posted by benjulmag

Snowman,

Not sure what you are saying. But to be clear, if each individual has a 90% chance of being a Knickerbocker, the probability of all six individuals being Knickerbockers is 0.9^6 which equates to 53%. The probability of only one of the members being a Knickerbocker is 1 - (0.1^6) which equates to the 99.9999% you cite. For it to be a Knickerbocker group photo, the relevant probability would be the 53%, not the 99.9999%.

We're not quite saying the same thing. Your math is correct if the question is phrased as "what is the probability that all 6 men are indeed a match for the 6 people Steve thinks they are?"

But that's not quite the same question I was answering above. If this is indeed a Knickerbockers photo, then the subjects in the photo are not independent of one another (independent in the statistical sense). In other words, if one of them is indeed a Knickerbocker, then that increases the likelihood that a second person is also a Knickerbocker. And if 2 are known to be Knickerbockers, then again, it increases the likelihood that a 3rd is, etc. Knickerbockers are likely to be photographed together. So my framing of the question "what are the odds that this is a Knickerbockers photo?" approaches it with that dependence structure in mind. It basically calculates what the odds are of all of his 90% Knickerbocker matches to be wrong rather than what the odds are for each one to be correct independently. My approach allows for, say, 5 of his 6 matches to be correct but him mistaking the identity of the 6th one, thus still making the photo a "Knickerbockers" photo.

[Snowman]

While I definitely can't claim that I'm 100% convinced, I will say that the resemblances in numerous facial features across the group is pretty remarkable. I'm definitely leaning toward yes, this is a photo of the Knickerbockers based on the resemblances alone. The 1862 photo is completely hacked together though. Legs are drawn on, torsos cut and pasted, shadows on different angles of the faces, etc. The subjects in that photo could have been taken across a pretty broad timeline, I would argue. There are at least 4 of the 6 that to me look almost like dead ringers.

That said, I'm also intrigued by the historical aspect of the photography used during that time and respect the knowledge of those who have studied it, as well as the history of the attire and where that might place this photo timeline-wise.

[SteveS]

Thank you so much, Snowman! After driving myself nuts with facial-match programs and 19th-century men's fashions, etc , I boiled it down to exactly what you said. The bare basics. It seems awfully unlikely that this many matches of unique features among this many people would happen by accident.