strata

Examples of strata in the following topics:

• Three sampling methods (special topic)

  • The population is divided into groups called strata.
  • The strata are chosen so that similar cases are grouped together, then a second sampling method, usually simple random sampling, is employed within each stratum.
  • In the baseball salary example, the teams could represent the strata; some teams have a lot more money (we're looking at you, Yankees).
  • Strati ed sampling would be a challenge since it is unclear how we would build strata of similar individuals.
  • In the middle panel, stratified sampling was used: cases were grouped into strata, and then simple random sampling was employed within each stratum.

• The Fossil Record as Evidence for Evolution

  • The observation that certain fossils were associated with certain rock strata led 19th century geologists to recognize a geological timescale.
  • The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record.
  • The development of radiometric dating techniques in the early 20th century allowed geologists to determine the numerical or "absolute" age of various strata and their included fossils.

• Deviance

  • Karen Halnon of Pennsylvania State University studies informal deviance and focuses on what she calls "deviance vacations," whereby people of a certain socioeconomic status voluntarily enter another, usually lower, social strata.
  • Karen Halnon of Pennsylvania State University studies informal deviance and focuses on what she calls "deviance vacations," whereby people of a given socioeconomic status voluntarily enter a different, often lower, social strata.

• Carbon Dating and Estimating Fossil Age

  • Stratigraphy is the science of understanding the strata, or layers, that form the sedimentary record.
  • Strata are differentiated from each other by their different colors or compositions and are exposed in cliffs, quarries, and river banks.
  • The layers of sedimentary rock, or strata, can be seen as horizontal bands of differently colored or differently structured materials exposed in this cliff.
  • The deeper layers are older than the layers found at the top, which aids in determining the relative age of fossils found within the strata.

• Reference Groups

  • For example, an individual in the U.S. with an annual income of $80,000, may consider himself affluent if he compares himself to those in the middle of the income strata, who earn roughly $32,000 a year.
  • For example, an individual in the U.S. with an annual income of $80,000, may consider himself affluent if he compares himself to those in the middle of the income strata, who earn roughly $32,000 a year.

• Structure of the Skin: Epidermis

  • In order from the deepest layer of the epidermis to the most superficial, these layers (strata) are the:
  • These changes are, in part, what give the strata their unique characteristics.
  • Outline the progression of kerantinocytes through epidermal strata from deepest to most superficial

• Financing the US Government

  • For example, income taxes due to their progressive nature are used to equitably derive revenue by differentiating tax rates by income strata.

• Blastocyst Formation

  • Before gastrulation, the cells of the trophoblast become differentiated into two strata.

• Introduction to deviance

  • Her research focuses on what she calls "deviance vacations," where people of certain socioeconomic status descend to lower strata.

• Metabolic Functions

  • Vitamin D is produced in the two innermost strata of the epidermis, the stratum basale and stratum spinosum.