Stratification may refer to:

Mathematics

Stratification (mathematics) Stratification has several usages in mathematics. In mathematical logic In mathematical logic, stratification is any consistent assignment of numbers to Predicate (logic), predicate symbols guaranteeing that a unique formal Interpretation (logic) ...

, any consistent assignment of numbers to predicate symbols * Data stratification in statistics

Earth sciences

Stable and unstable stratification Stable stratification of fluids occurs when each layer is less dense than the one below it. Unstable stratification is when each layer is denser than the one below it. Buoyancy forces tend to preserve stable stratification; the higher layers ...

* Stratification, or

stratum In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

, the layering of rocks *

Stratification (archeology) Stratigraphy is a key concept to modern archaeological theory and practice. Modern excavation techniques are based on stratigraphic principles. The concept derives from the geological use of the idea that sedimentation takes place according t ...

, the formation of layers (strata) in which objects are found *

Stratification (water) Stratification is the separation of water in layers. Two main types of stratification of water are uniform and layered stratification. Layered stratification occurs in all ocean basins. Stratified layers act as a barrier to the mixing of water, whi ...

, the formation of water layers based on temperature (and salinity, in oceans) *

Lake stratification Lake stratification is the tendency of lakes to form separate and distinct thermal layers during warm weather. Typically stratified lakes show three distinct layers, the Epilimnion comprising the top warm layer, the thermocline (or Metalimnion): ...

, the formation of water layers based on temperature, with mixing in the spring and fall in seasonal climates. *

Atmospheric stratification The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...

, the dividing of the Earth's atmosphere into strata *

Inversion (meteorology) In meteorology, an inversion is a deviation from the normal change of an atmosphere, atmospheric property with altitude. It almost always refers to an inversion of the air temperature lapse rate, in which case it is called a temperature in ...

Social sciences

Social stratification Social stratification refers to a society's categorization of its people into groups based on socioeconomic factors like wealth, income, race, education, ethnicity, gender, occupation, social status, or derived power (social and political). As ...

, the dividing of a society into levels based on power or socioeconomic status

Biology

Stratification (seeds) In horticulture, stratification is a process of treating seeds to simulate natural conditions that the seeds must experience before germination can occur. Many seed species have an embryonic dormancy phase, and generally will not sprout until this ...

, where seeds are treated to simulate winter conditions so that germination may occur *

Stratification (clinical trials) Stratification of clinical trials is the partitioning of subjects and results by a factor other than the treatment given. Stratification can be used to ensure equal allocation of subgroups of participants to each experimental condition. This may ...

, partitioning of subjects by a factors other than the intervention *

Stratification (vegetation) Stratification in the field of ecology refers to the vertical layering of a habitat; the arrangement of vegetation in layers. It classifies the layers (sing. ''stratum'', pl. ''strata'') of vegetation largely according to the different heights to w ...

, the vertical layering of vegetation e.g. within a forest *

Population stratification Population structure (also called genetic structure and population stratification) is the presence of a systematic difference in allele frequencies between subpopulations. In a randomly mating (or ''panmictic'') population, allele frequencies are ...

, the stratification of a genetic population based on allele frequencies

Linguistics

Stratification (linguistics) In linguistics, stratification refers to the idea that language is organized in terms of hierarchically ordered strata (such as phonology, morphology, syntax, and semantics). This notion can be traced back to Saussure's dichotomy between signified ...

, the idea that

language Language is a structured system of communication. The structure of a language is its grammar and the free components are its vocabulary. Languages are the primary means by which humans communicate, and may be conveyed through a variety of met ...

is organized in hierarchically ordered strata (such as

phonology Phonology is the branch of linguistics that studies how languages or dialects systematically organize their sounds or, for sign languages, their constituent parts of signs. The term can also refer specifically to the sound or sign system of a ...

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

syntax In linguistics, syntax () is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure ( constituency) ...

, and

semantics Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy Philosophy (f ...

Mathematics

Earth sciences

Social sciences

Biology

Linguistics

See also