5.3.3 Collecting Samples Sample Size For student handout, print out only slides 1-6

Sample Size: How Much is Enough? Does the size of the sample matter? Sample must be large enough to give good representation of population Sample must be small enough to be manageable

Sample Size: How Much is Enough? Does the size of the sample matter? If population is more-or-less uniform, sample can be smaller If population is more diverse, sample size must be larger to accommodate

How Much is Enough? The following slides are data displays showing random samples of 30, 50, 100, 300, and 500 students from the United Kingdom, South Africa, and Australia, ranging in age from 7 to 19 years. Each dot represents one student. Do 30, 50, 100, 300, 500 cases make up a large enough sample to compare students by Gender? Country? Age?

Is 30 enough?

Is 50 enough?

Is 100 enough?

Is 300 enough?

Is 500 enough?

Sampling Assignment Choose 3 different sampling methods Use each method to create a sample of 10 students from the class Your samples should not include you Explain how you developed each sample List the students (by number) in each sample Discuss the advantages and disadvantages of each sample (how representative it is of the population) Due Thursday at the beginning of class