Video Lecture Notes: Blocking Variables and Sampling Methods

Vocabulary flashcards covering key ideas about blocking variables, stratified and random sampling, exclusion criteria, and how blocking helps reveal differences in experiments.

Blocking variable

A variable used to group experimental units into blocks to reduce variability within blocks and to reveal differences between treatments.

Stratified sampling

A sampling method that divides the population into strata (subgroups) based on a blocking variable and samples from each stratum to ensure representation and to compare differences across strata.

Random sampling

A sampling method in which every member of the population has an equal chance of being selected, aiming for unbiased representation.

Exclusion criteria

Rules for excluding certain participants from a study to remove sources of bias or unwanted variation and to align the sample with research goals.

Blocking design

An experimental design where units are grouped into homogeneous blocks before applying treatments, reducing within-block variability to better detect treatment effects.

Control for a variable

The process of accounting for or holding constant a variable's influence so it does not confound the relationship between the main variables under study.