stratified random sample: meaning, definition, pronunciation and examples
C1/C2Formal, Academic, Technical
Quick answer
What does “stratified random sample” mean?
A method of sampling that divides a population into distinct subgroups (strata) and then draws a random sample from each subgroup.
Audio
Pronunciation
Definition
Meaning and Definition
A method of sampling that divides a population into distinct subgroups (strata) and then draws a random sample from each subgroup.
A sophisticated statistical technique ensuring representation across key demographic or categorical variables, often used when researchers suspect these variables influence the outcome being studied. It increases precision and reduces sampling error compared to simple random sampling.
Dialectal Variation
British vs American Usage
Differences
No significant difference in core meaning or usage. Spelling conventions follow standard UK/US patterns (e.g., 'technique' vs. 'technic' is not relevant here).
Connotations
Equally formal and technical in both variants. Associated with rigorous research methodology.
Frequency
Equally common in academic and research contexts in both regions.
Grammar
How to Use “stratified random sample” in a Sentence
Researchers [verb] a stratified random sample of [population] stratified by [variable].The study utilised a stratified random sample to ensure [goal].Vocabulary
Collocations
Examples
Examples of “stratified random sample” in a Sentence
verb
British English
- We will stratify the sample by region and socio-economic status before random selection.
- The polling company stratified the electorate prior to sampling.
American English
- The researchers stratified the population by zip code and income bracket.
- To ensure fairness, the jury pool was stratified by demographic factors.
adverb
British English
- The households were sampled stratifiedly, which was methodologically sound.
- (Note: This form is extremely rare; 'using a stratified method' is preferred.)
American English
- (Rarely used as an adverb; the adjectival form is standard.)
adjective
British English
- The stratified sampling approach yielded more precise estimates.
- They adopted a stratified random design for the national census.
American English
- A stratified random technique was critical for the clinical trial.
- The stratified analysis revealed differences hidden in the aggregate data.
Usage
Meaning in Context
Business
Used in market research to ensure customer segments (e.g., by age, income) are proportionally represented in surveys.
Academic
Fundamental in social sciences, medicine, and population studies for designing robust, generalisable research.
Everyday
Virtually never used in casual conversation.
Technical
A core methodology in statistics, survey methodology, and quantitative research design.
Vocabulary
Synonyms of “stratified random sample”
Strong
Neutral
Weak
Vocabulary
Antonyms of “stratified random sample”
Watch out
Common Mistakes When Using “stratified random sample”
- Confusing it with 'cluster sample' (which samples intact groups).
- Omitting 'random' (stratified sample without random selection within strata is a 'stratified quota sample').
- Using it to describe any non-simple random sample.
FAQ
Frequently Asked Questions
No. It is more efficient and precise when the stratification variables are strongly related to the outcome of interest. If they are not, it offers little advantage and adds complexity.
In stratified sampling, you sample from ALL strata (subgroups). In cluster sampling, you randomly select a few intact clusters (e.g., schools, city blocks) and sample everyone within them. They solve different problems: stratification increases precision, clustering reduces cost and practical difficulty.
Yes. In 'proportionate stratification', the sample size from each stratum is proportional to the stratum's size in the population. In 'disproportionate stratification', you may oversample a small stratum to ensure you have enough data to analyse it reliably.
Yes, for it to be a 'stratified *random* sample'. Without random selection within strata, it becomes a form of non-probability or quota sampling, which limits statistical inference.
Stratified random sample is usually formal, academic, technical in register.
Stratified random sample: in British English it is pronounced /ˌstræt.ɪ.faɪd ˈræn.dəm ˈsɑːm.pəl/, and in American English it is pronounced /ˌstræt̬.ə.faɪd ˈræn.dəm ˈsæm.pəl/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None. This is a technical term.”
Learning
Memory Aids
Mnemonic
Imagine a layered cake (strata). To taste it fairly, you take a random forkful from each layer (sample), not just from the top.
Conceptual Metaphor
FAIR REPRESENTATION AS LAYERED EXTRACTION. The population is conceptualised as a rock with distinct strata; a proper sample must drill into each layer.
Practice
Quiz
What is the primary purpose of stratification before random sampling?