PREDICTIONS – 10 Years Later - Santa Fe Institute

3. INANIMATE PRODUCTION LIKE ANIMATE REPRODUCTION
“I could try,” I said, “if I knew how much you have
grown every year so far. I have only a few measurements
from when you were a little baby.”
“At school they measure us every year from kindergarten,”
she said. “The nurse keeps a record of all these
numbers on a card.”
The next day she came home with a Xerox copy of her
school card containing height and weight measurements for
the last six years. “Here you are,” she said. “Now how tall
will I be?”
I turned on my personal computer and typed in the numbers.
She stood next to me radiant with doubting
expectation.
The data set was not complete. There was a gap between
ages one and four. I tried to compensate by adjusting the
weights accordingly. At the end, I said rather triumphantly,
“You will be five feet six inches.”
First she had to appreciate how tall that was. We took the
tape measure, made a mark on the door, and looked at it
from different angles. She seemed pleased. But soon she was
concerned again. “How sure are you?”
She was only ten; she knew nothing about measurement
errors, statistics, standard deviations or uncertainties from
fitting procedures. But her instinct was warning her about the
magnitude of the uncertainties in determining a final plateau
from early measurements. I didn’t want to disappoint her,
but I didn’t want to lie to her, either. I made a quick calculation,
“sprinkled” with optimism, using Table III from
Appendix B.
“You will be five feet six to within ten percent” I decided.
“What does ten percent mean,” she asked.
“It means you will most probably be between four feet
eleven and six feet one,” I offered timidly.
A moment of reflection, some more visualizations, and then
she turned away disappointed and mumbling, “Big deal.”
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