PBS
Pbs Teachers: Scientific American: Deep Crisis: Salmon Counting
In this lesson, students can explore the techniques of census and population counting by inferring numbers of a virtual population illustrated within a rectangular sampling grid, and observing the accuracy of the technique in relation to...
Web Center for Social Research Methods
Research Methods Knowledge Base: Sampling in Research
Site discusses the use of sampling in research. The key statistical terms used in sampling are linked for the user to quickly find definitions. The major concepts of probability and nonprobability are also highlighted.