AP Statistics: Unit 3 Data Collection Mastery

Population

The entire group of individuals we want information about.

Census

A study that attempts to collect data from every individual in the population.

Sample

A subset of individuals in the population from which we actually collect data.

Inference

The process of drawing conclusions about a population based on data from a sample.

Generalizability

The ability to apply findings from a sample to the larger population.

Simple Random Sample (SRS)

A sample of size n chosen so that every group of n individuals has an equal chance to be selected.

Stratified Random Sampling

A method where the population is divided into homogeneous groups and SRS is performed within each group.

Cluster Sampling

A method where the population is divided into heterogeneous groups and whole clusters are selected for study.

Systematic Random Sampling

Selecting individuals from an ordered population by choosing one of the first k individuals and selecting every k-th individual thereafter.

Voluntary Response Bias

Bias that occurs when individuals can choose whether to participate, often leading to a skewed result.

Convenience Sampling

Choosing individuals who are easiest to reach, leading to potential bias.

Undercoverage

When some members of the population cannot be chosen due to not being included in the sampling frame.

Nonresponse Bias

Bias that occurs when individuals selected for the sample do not respond or cannot be contacted.

Response Bias

A systematic pattern of incorrect responses due to various factors like question wording or interviewer influence.

Sampling Method Bias

Bias resulting from the way a sample is chosen, usually due to non-random methods.

Implementation Bias

Bias that occurs during the execution of a study, despite an initially sound sampling plan.

Precision

Refers to the closeness of repeated measurements or survey results to each other.

Accuracy

Refers to how close a measurement or survey result is to the actual population parameter.

Stratification

The process of dividing a population into subgroups for study.

Cluster

A heterogeneous group that represents a mini-population within a larger population.

SRS

An acronym for Simple Random Sample.

Census

A comprehensive survey that gathers data from every member of the population.

Randomization

The process of using chance to select individuals for a sample, reducing potential bias.

Random Assignment

Assigning participants in an experiment randomly to ensure groups are comparable.

Key Terms

Important vocabulary and definitions relevant to statistics and sampling methods.

Bias vs. Variability

Bias relates to accuracy of results, while variability relates to the precision of repeated results.

Data Collection

The systematic approach to gathering information for analysis.