Precision Measurements, Do They Matter?

[dlbristol]

As a math guy, I think this might be a great place to add the "precision vs accuracy" that sometimes bothers students. Precision in calculations is a function of how small the original measurement units are. A measurement in miles is less precise than the same distance measured in feet. Accuracy is a function of how well a calculated number reflects the actual measurement. There in lies part of the issue here in this thread. I can measure the thickness of a piece of stock with my digital calipers and be precise to +/- .001 in, but if I don't read it correctly or cut it badly, I will have poor accuracy. The idea that the measurement is not as important as the actual fit is correct from the mathematics of the system. I think that the use of a "story stick" probably illustrates this well. There not any way to determine precision ( mathematics wise) )because there is no unit, Yet the results of using them is very accurate. You guys are right on. So many people say "I never use math" and yet have a very real grasp of the deeper concepts. Thanks fro a good example to use with my next tutoring client!