TIPsters....
Here is a question I have not seen addressed before....
My stats class typically draws some students from Chemistry and Biology.
Recently, one of the chemistry students was having a lot of trouble
getting the correct answers in her computations. I went through her work,
and discovered that she was applying the rules for "significant figures"
to her statistical calculations. In other words, she was rounding her
calculations so that the result of the calculation never had a degree of
precision greater than the degree of precision in the original data.
I have not thought this through, but it looks like application of
"significant figures" to statistical calculations will virtually always
result in an "incorrect" calculation.
For example, if our original data are expressed only in whole numbers, it
seems like a Pearson r could only take on three values: -1.00, 0.00, and
1.00.
For now, I have simply told my students to "forget about everything you
have ever learned about significant figures..." I would prefer a better
answer. Any suggestions?
-- Jim
P.S. My analysis may be completely incorrect - as I said, I have not
thought through this completely....
