STAT 119 Chapter Notes - Chapter 8–10 : Sampling Frame, Sample Size Determination, Statistical Parameter
Document Summary
Idea 1: sample examine a part of the whole. Sample survey - designed to ask questions of a small group of people in the hope of learning something about the entire population. Samples that over or underemphasize some characteristics of the population are said too be biased. Biased - summary characteristics of a sample differ form the corresponding characteristics of the population it is trying to represent. Best strategy is to select individuals for the sample at random. Can protect against factors that you aren"t aware of. Protects us by giving us a representative sample even for effects we are unaware of. We select participants are random which helps us to represent all the features of our population. Making sure that on average the sample lookalike the rest of the population. Essential feature of randomness is that the selection is fair. Idea 3: the sample size is what matters.
