10.1 Sample Size Axioms

10.1.1 Important Points about Sampling

Sampling method (not sample size) is related to representativeness.

Only a probability sample (random sample) is truly representative of a population.

Sample size determines accuracy of findings.

10.1.2 Sample Accuracy

Sample accuracy（样本精确度）: refers to how close a random sample’s statistic is to the true population’s value it represents

Important points:

Sample size is not related to representativeness（样本容量与样本代表性无关）

Sample size is related to accuracy（样本容量影响样本结论的准确性）

10.1.3 Two Types of Error

Nonsampling error（非抽样误差）: pertains to all sources of error other than sample selection method and sample size

Sampling error（抽样误差）: involves sample selection and sample size