Week 6.2 - Sampling &amp; Experiments

# The bigger the sampling ratio small p opulations

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Unformatted text preview: more practical too. Types of Probability Samples Simple Random Easiest to understand, model for other types Create a sampling frame for all cases Select cases using a purely random process Random- number table Computer program Cluster Create a sampling frame for larger cluster units and draw a random sample of cluster units Create a sampling frame for cases within each selected cluster unit and then draw a random sample of these cases Can have multiple cluster stages Types of Probability Samples Stratiﬁed Create a sampling frame for each of several categories of cases Draw a random sample from each category Combine these several samples Systematic Create a sampling frame Calculate the sampling interval 1/k Choose a random starting place Then, take every 1/k case Sample Size Depends on three things: Degree of accuracy required; degree of variability in population; number of variables examined simultaneously in data analysis Decide using statistical procedures (outside the scope of this course) Decide using “rules of thumb” The smaller the population, the bigger the sampling ratio Small P opulations (under...
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## This note was uploaded on 02/03/2014 for the course SOC 293 taught by Professor N/a during the Spring '10 term at SUNY Buffalo.

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