Chinese Gender Predictor
One mom did an experiment with the Chinese Gender Chart. She called on her Facebook friends to volunteer as many birth dates as possible to come up with a percentage of right and wrong. She ended up with 50 birthdays, which is a pretty good control group for a statistical experiment.
Out of 50 birthdays, the test predicted 43 of them correctly, 7
incorrectly. 43 divided by 50 is .83, making the test 83% effective
according to her experiment.
Of course, as we know this number could have changed based on how many
people she used, but she noticed a pattern as well. She would get a long
string of correct predictions and then a block of about 2 or 3 incorrect
all at once.
Another interesting note, the times it was incorrect was always for siblings, for example:
She asked her friend for his and his siblings birthdays, it was correct for
him, incorrect for both of his siblings. Same thing with her other friend , correct for her, incorrect for both siblings. It was also incorrect for her aunt and both of her kids, but correct for her brother.It was never wrong for people who provided her a single birthday.