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  2. Area sampling frame - Wikipedia

    en.wikipedia.org/wiki/Area_sampling_frame

    A sampling frame is often defined as a list of elements of the population we want to explore through a sample survey. A slightly more general concept considers that a sampling frame is a tool that allows the identification and access to the elements of the population, even if an explicit list does not exist. [1] Traditional sampling frames are ...

  3. Sampling frame - Wikipedia

    en.wikipedia.org/wiki/Sampling_frame

    In statistics, a sampling frame is the source material or device from which a sample is drawn. [1] It is a list of all those within a population who can be sampled, and may include individuals, households or institutions. [1] Importance of the sampling frame is stressed by Jessen [2] and Salant and Dillman. [3]

  4. Systematic sampling - Wikipedia

    en.wikipedia.org/wiki/Systematic_sampling

    The most common form of systematic sampling is an equiprobability method. [1] This applies in particular when the sampled units are individuals, households or corporations. When a geographic area is sampled for a spatial analysis, bi-dimensional systematic sampling on an area sampling frame can be applied. [2]

  5. Simple random sample - Wikipedia

    en.wikipedia.org/wiki/Simple_random_sample

    The concept can be extended when the population is a geographic area. [4] In this case, area sampling frames are relevant. Conceptually, simple random sampling is the simplest of the probability sampling techniques. It requires a complete sampling frame, which may not be available or feasible to construct for large populations. Even if a ...

  6. Coverage error - Wikipedia

    en.wikipedia.org/wiki/Coverage_error

    Her sampling frame might be a list of third-graders in the school district (sampling frame). Over time, it is likely that the researcher will lose track of some of the children used in the original study, so that her sample frame of adults no longer matches the sample frame of children used in the study.

  7. Total survey error - Wikipedia

    en.wikipedia.org/wiki/Total_survey_error

    Sampling error, which occurs in sample surveys but not censuses results from the variability inherent in using a randomly selected fraction of the population for estimation. Nonsampling error, which occurs in surveys and censuses alike, is the sum of all other errors, including errors in frame construction , sample selection, data collection ...

  8. Quadrat - Wikipedia

    en.wikipedia.org/wiki/Quadrat

    [1] [2] A quadrat is suitable for sampling or observing plants, slow-moving animals, and some aquatic organisms. A photo-quadrat is a photographic record of the area framed by a quadrat. It may use a physical frame to indicate the area, or may rely on fixed camera distance and lens field of view to automatically cover the specified area of ...

  9. Laboratory specimen - Wikipedia

    en.wikipedia.org/wiki/Laboratory_specimen

    A laboratory specimen is sometimes a biological specimen of a medical patient's tissue, fluids, or other samples used for laboratory analysis to assist in differential diagnosis or staging of a disease process. These specimens are often the most reliable method of diagnosis, depending on the ailment.