POLI 311 Lecture Notes - Lecture 15: Simple Random Sample, Nonprobability Sampling, Quota Sampling
2 Apr 2016
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Document Summary
Having a large sample is no guarantee of representaiveness. Probability sample: every member of the populaion has a known, non-zero probability of inclusion in the sample. Someimes there"s an equal probability of each member being included. Advantages of probability sampling: avoids conscious or unconscious bias, allows the use of inferenial stats to esimate the likelihood that sample results difer from those observed from studying the enire populaion. Types of random samples: simple random sample: Most basic design, forms basis for more complex designs. Gives every member of populaion an equal probability of selecion. Gives every combinaion of members of the populaion an equal probability of selecion. Disadvantages: can produce extreme samples because every possible combinaion of people has an equal probability of inclusion. Beginning with a randomly selected person from among the irst k people, select every kth person. First case must be selected randomly (by the number table of number generator) and then the rest will be random.
