General Science

  • noun the formation of several layers in substances such as sedimentary rocks, or water in a lake or air in the atmosphere


  • The separation of overwet or overvibrated concrete into horizontal layers with increasingly lighter material toward the top. Water, laitance, mortar, and coarse aggregate will tend to occupy successively lower positions in that order.
  • A layered structure in concrete resulting from placing of successive batches that differ in appearance.
  • The occurrence in aggregate stockpiles of layers of differing grading or composition.
  • A layered structure in a rock formation.
  • The flow at the junction of two airstreams in layers that prevent the proper mixing of the two airstreams.


  • noun the structure of a questionnaire which should help to ensure reliable answers and make it easy to evaluate results
  • noun a framework for the selection of a sample that ensures that it adequately represents the entire group of people surveyed