SOCI 3700 Lecture Notes - Lecture 6: Confidence Interval, Nth Metal, Sampling Frame
3 Apr 2019
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Document Summary
A well-designed probability sample is one that is likely to be representative of the population from which it was selected because it is random. Although a random sample does not contain systematic bias, it will have some degree of sampling error due to chance. To deal with this, researchers take into account the properties of a sampling distribution, a hypothetical distribution of a statistic across all the random samples that could be drawn from a population. There are two key things that impact the amount of error that could be present in a random sample: Confidence levels are the probability that an estimate includes the population parameter. The range implied by the margin of error is called the confidence interval. Ex: according to a gallup poll, 43% of americans approve of the job the president is going, with a margin of error of 3 percentage points.
