What does stratified mean?
Stratified describes something divided into layers, levels, or ranked categories. The word is especially important in geology, where it refers to rock or sediment deposited in successive layers, and in sociology, where it describes a society whose population is arranged into unequal groups based on wealth, status, education, gender, race, or access to resources. In research, "stratified sampling" divides a population into subgroups and then draws samples from each, helping researchers include people with differing characteristics. The term is more precise than simply "divided," because it often suggests order, hierarchy, or layering rather than a random collection of separate parts. Although the metaphor originally comes from physical strata, it is now widely used to describe hidden patterns of advantage and disadvantage. Its social meaning makes it valuable in discussions of inequality, but it should not be used when division is merely incidental or when no hierarchy or layering is implied.
Arranged in layers, levels, or ranked categories; especially divided into unequal social groups.
"Access to high-quality education remains stratified by income and postcode."
The social sense often carries an implication of hierarchy and unequal access or opportunity.
To arrange something into layers, levels, or categories; to divide a population or sample into distinct groups.
"Researchers stratified the survey by age and region before collecting responses."
This is the past tense and past participle of "stratify" and is most often used in technical, academic, or social-science writing.
Stratification is the hidden architecture of a society: beneath the appearance of equal opportunity, layers of advantage and disadvantage shape nearly every life.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does stratified come from?
Stratified was formed in English from the verb "stratify," which in turn comes from Latin "stratum," a layer or bed and, by extension, a class of people or things. The ultimate Latin root "sternere" means "to strew" or "to spread out," reflecting the original sense of laying material in layers. Related English words include "stratum," "stratosphere," and "substratum."
Related word forms
How stratified is actually used
In academic and sociological writing, the adjective often implies that categories are ranked or unequal rather than merely separate. The verb is most common in technical and social-science contexts; everyday speech more often uses related forms such as "stratification."
Easily confused with stratified
Stratified means divided into layers or social categories, whereas striated means marked with narrow lines or streaks.