I don’t believe I have yet succumbed to either the bogus or destructive. If I don't have enough data to even speculate, I don't. I don't mind blank spots on the record, as it reminds me where I need to conduct more research.
I have utilized both fuzzy and speculative math, but always made notes as to the logic that led to the conclusion. My best example is the birth date of my third great grandmother Gitel Slupsky, mother of Selig Dudelsack. Both of them changed their surname to Feinstein in America.
Gitel immigrated with her son, Selig, in 1890, and is buried in St. Louis. I have visited, and photographed her tombstone. It says she died on the 19th of Av in 5666. A Hebrew-Gregorian date converter tells me this is August 10, 1906. (Or August 9th, since the Hebrew day starts at sunset the night before.) The tombstone also says she was born in 1831.
However, her death record says she was 60 years, 5 months, and 21 days old when she died. (At least according to the abstract – I haven’t seen the original. The address on the death record matches the address on the 1900 and 1910 census for the family, so there is no confusion of names.)
Finally, just to confuse matters further, the 1900 census says she was born in January of 1840.
I have chosen Feb 17, 1846 as the date to enter on her record, because there is logic behind it, and it is nice to have a logical exact date, but I've described where I got that date, and all the variations from other documents in my notes.
As a side note – Arlene Eakle leads into her discussion on math with the ‘gaffe’ that Senator Obama made when he said he had visited 57 states. For those who are confused how one can make that gaffe even due to lack of sleep, reading the Snopes article on this topic is revealing. Many people think Obama said 57 when he meant 50. However, he had visited 47 states at the time, and it’s not too difficult to imagine where someone might slip and say ‘fifty’ instead of ‘forty.’