PO217 Lecture 7: Small n Research
Document Summary
Problem: the populations we wish to study are almost always so large that we are unable to gather information from every case. Solution: we choose a sample a carefully chosen subset of the population and use information gathered from the cases in the sample to generalize to the population. In estimation procedures, statistics calculated from random samples are used to estimate the value of population parameters: population perameters, samples statistics. Parameter and statistic: statistics are mathematical characteristics of samples, parameters are mathematical characteristics of populations, statistics are used to estimate parameters. Theoretical normal curve: theoretical, bell shaped, unimodal, symmetrical, unskewed, mode, median and mean are same value. The sampling distribution: every application of inferential statistics involves 3 different distributions, population: empirical; unknown, sampling distribution: theoretical; known, sample: empirical; known. Information from the sample is linked to the population via the sampling distribution: sample sampling distribution population, sampling distribution in inferential statistics links the sample with the population.
