Sample size – Jim Hogan
How big should a sample be?
Jim noticed in schools that the usual response to “How many should I sample?” was “30”. Teachers simply told students to take samples of 30. Why? This power point developed with teachers in the Eastern Bay of Plenty shows how students can investigate and answer this question and it also generates a model and explanation of the 1/√n in the confidence interval formulae. I used iNZight but any sampling package would do.
Jim Hogan also has resources and ideas on integrating probability and allowing students to experience randomness throughout the curriculum.
