representative sample
Học thuậtThân thiện
Definition
Noun: A subset of a larger population, selected in such a way that it accurately reflects the characteristics, diversity, and proportions of the entire population. This allows for conclusions drawn from the sample to be reliably generalized to the whole group.
Usage
A "representative sample" is a key concept in statistics, research, and polling. It is used to describe a carefully chosen group of individuals, items, or data points that stand in for a larger, often unmanageable, whole. The goal is to achieve accuracy and validity in studies without examining every single member of the population.
Examples
Advanced Usage
- "To draw a representative sample": This phrase describes the process of selecting such a sample.
- The researchers used random digit dialing to draw a representative sample of voters.
- "Statistically representative sample": Emphasizes that the sample's representativeness is confirmed through statistical methods.
- The margin of error is only valid if you have a statistically representative sample.
Variants and Related Words
- Stratified Sample (Noun): A specific type of representative sample where the population is first divided into subgroups (strata) based on shared characteristics (e.g., age, income), and then random samples are taken from each stratum. This ensures all key subgroups are proportionally included.
- They obtained a stratified sample by ensuring proportional representation from each income bracket.
- Random Sample (Noun): A sample where every member of the population has an equal chance of being selected. This is a fundamental technique for achieving a representative sample, though a simple random sample may not always be perfectly representative by itself.
- Cross-section (Noun): Often used informally to mean a representative sample, implying the sample includes a typical variety of people or things.
- The audience was a cross-section of the general public.
Synonyms
- Cross-section: A sample that is representative of the different parts of a whole.
- Microcosm: Something (such as a place or an event) that is seen as a small-scale representation of something much larger.
Antonyms
- Biased sample: A sample that does not accurately represent the population, often due to flawed selection methods.
- Non-representative sample: A sample that is not typical of the larger population.
Noun
- the population is divided into strata and a random sample is taken from each stratum