POS 3713 Chapter Notes - Chapter 6: Sampling Distribution, Frequency Distribution, Standard Error
17 Apr 2017
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2 types of data sets: data about the population. It is relatively rare that scientists will make use of data pertaining to the entire population: data drawn from a sample. Sample: a subset of cases that is drawn from an underlying population. Sample does not always imply random sample; samples may be nonrandom (samples of convenience) The majority of analyses are done on sample data, not population data. We are not interested in the properties of the sample, but what it helps us learn about the underlying population. Statistical inference: we use what we know to be true about one thing (the sample) to infer what is likely to be true about another thing (the population) This process of statistical inference involves a degree of uncertainty. Independent outcomes: 2+ outcomes are independent if the realization of one outcome does not a ect the realization of other outcomes. Key probability properties: all outcomes have some probability ranging from 0 to 1.
