Title

Population versus Sampling Statistics

Document Type

Article

Publication Date

5-2008

Abstract

When scientists draw random samples to be measured they expect their results will be accurate, assuming all systematic errors have been removed from the experiment. Unlike systematic errors, random errors cannot be removed from the experiment – only reduced. If several replicates are measured for each sample, random errors are mathematically minimized and are relegated to affecting precision, not accuracy. For some students, the difference between accuracy and precision is not clear enough for this to make sense. The solution is for students to interact with the statistics, which requires the laborious generation of multiple sets of random numbers, numerical comparisons, and graphical presentations of the data. The purpose of the spreadsheet exercise presented here is to remove the hurdle of constructing and generating such an interaction. The spreadsheet provides students with a self-led exercise that reinforces the statistics of sample and population distributions.