Chapter 10 - Sample Surverys Vocabulary

Elementary Statistics & Inference

Stratified Random Samples

The population is divided into several subpopulations, and then random samples are drawn from each of these subpopulations.

Cluster Samples

A sampling design in which entire groups are chosen at random.

Systematic Samples

A sample drawn from selecting individuals from an organized sampling frame. 

Multistage Samples

A type of random sampling that combines several sampling methods.

Voluntary Response Samples

A sample in which individuals can choose on their own whether or not to participate.

Convienence Samples

These samples consist of individuals who are readily available for assessment. 

Undercoverage

A sampling example that samples in a way that gives part of the population less representation in the sample than it has in the population. 

Nonresponse Bias

Bias is introduced when a large fraction of those samples fail to respond.

Response Bias

Anything in a survey design that influences responses falls under this bias. This could be things such as the wording of the question or favoring one response.

Population

The ENTIRE group of individuals or instances about whom we hope to learn.

Sample

A (representative) subset of a population.

Sample Survey

A study that asks questions of a sample drawn from some population in the gope of learning something about the entire population. 

Bias

Any systematic failure of a sampling method to represent its population.

Randomization

Each individual or instance is given a fair, random chance of selection.

Sample Size

The numbers of individuals in a sample.

Population Parameter

A numerically valued attribute of a model for a population.

Statistic, sample statistic

Values calculated from sampled data.

Representative

A sample is said to be this if the statistics computed from it accurately reflect the corresponding population parameters.

Simple Random Sample (SRS)

A sample in which each set of n elements in the population has an equal chance of selection.

Sampling Variability

The natural tendency of randomly drawn samples to differ, one from another.