-->can be described as the correctness of a measurement
Precision-->how close the measurement (or average measurement) comes to the accepted or real value
-->can be described as the exactness of a measurement
*no measurement is exact
-every measurement is only one's best estimate, as it has some degree of uncertainty
-measurements are only exact when they are counted
eg. a family of 4
-Uncertainty is expressed in the unit of measurement, not as a ratio or fraction
-there are 2 methods:
1. Make at least 3 measurements
2. Calculate the average between the measurements
3.Calculate the different between the average and the lowest or highest reasonal measurement. The largest difference will be the absolute uncertainty.
1. Make the best precise measurement, estimate to a fraction 0.1 if the smallest segment on the instrument scale.
Relative Uncertainty and Sig. Figs.
Relative Uncertainty=Absolute uncertainty/estimated measurement-relative uncertainty can be expressed as a percent, or with sig. figs.
Practice reading scales, and identifying the uncertainty of each measurement using method 2.
Watch this video! It'll help. (:
How to Read a Ruler
Written by Jialynn