In statistical terms, if a survey captures data from a specific group, what is this group called?

In statistical analysis, when a survey captures data from a specific group, that group is referred to as a sample. A sample is a subset of a larger population and is selected to represent that population in statistical studies. This allows researchers to draw conclusions about the whole population based on the data collected from the sample.

The concept of a sample is critical because it is often impractical or impossible to collect data from every individual in the population. By analyzing a smaller, manageable group, statisticians can make estimates and predictions that apply to the entire population, while also accounting for variances and potential biases in the data collection process.

The other terms mentioned serve different purposes in statistics. A population encompasses all individuals or observations of interest, strata refer to subgroups within a population often used in stratified sampling, and cohorts pertain to groups of individuals with a shared characteristic, typically used in longitudinal studies. Understanding these distinctions helps clarify the role of samples in statistical methodologies.