PSC 200 Lecture Notes - Lecture 7: Systematic Sampling, Simple Random Sample, Stratified Sampling
7 Dec 2017
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A sample is a number of cases drawn from a population. Population entirety of a group you wish to study (think of unit of analysis) We can never really capture an entire population. Instead we draw a sample that may be more or less representative of the population. % of all americans that support obama-care . Although pp is unknowable statistics allow us to estimate it and calculate the sample error or bias. The larger our n, the smaller our sample error. A list of units from which the sample is drawn. Ideally it should include every unit in the population. Selection is random, determined by the blind hand of chance - there are varying degrees of randomness in the various forms of probability sampling) Each unit in the sample frame has an equal non-zero chance of being. A probability sample in which cases/units sharing one or more characteristics are proportion to the group"s representation in the total population.
