Witness for the Prosecution
"What this court is interested in is facts. It is a fact that our
esteemed witness perceived a red uniform, the uniform of a Puzzlanian
soldier. It remains to be established whether what he perceived and what
actually was were the same," the young attorney began.
He asked the jury to consider the following improbable situation: a hundred
Puzzlanians all consecutively kill that one civilian, like Murder on an
extremely crowded Orient express. Of these, 80 are soldiers, and 20 are
civilian. What does the witness perceive?
Of the 80 red soldiers, the witness correctly identifies 68 as wearing
red, and the remaining 12 incorrectly as wearing green. Of the 20 green
civilians, the witness correctly identifies 17 as wearing green, and the
remaining 3 incorrectly as wearing red.
Now in the real case, we know the witness was seeing red, no pun intended.
As illustrated above, in 71 cases out of a hundred, the witness saw
red. These are the only ones we are concerned with. Of those, the witness
saw right 68 times. Since 68/71=~.9577, the witness's report of red is
reliable more than 95% of the time.
The General was convicted, and stripped of his command.