enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Nonprobability sampling - Wikipedia

    en.wikipedia.org/wiki/Nonprobability_sampling

    Such samples are biased because they give people with more social connections an unknown but higher chance of selection, [10] but lead to higher response rates. Judgment sampling or purposive sampling, where the researcher chooses the sample based on who they think would be appropriate for the study. This is used primarily when there is a ...

  3. Huffington Post / YouGov Public Opinion Polls

    data.huffingtonpost.com/yougov/methodology

    The sample is selected to approximately match the joint distribution of age, race, gender, and education in the 2016 American Community Survey (ACS). This is a purposive, rather than random, method of selection, designed to eliminate selection bias and non-coverage of the target population in the panel from which respondents were drawn.

  4. Sampling (statistics) - Wikipedia

    en.wikipedia.org/wiki/Sampling_(statistics)

    A visual representation of the sampling process. In statistics, quality assurance, and survey methodology, sampling is the selection of a subset or a statistical sample (termed sample for short) of individuals from within a statistical population to estimate characteristics of the whole population. The subset is meant to reflect the whole ...

  5. Sampling bias - Wikipedia

    en.wikipedia.org/wiki/Sampling_bias

    In statistics, sampling bias is a bias in which a sample is collected in such a way that some members of the intended population have a lower or higher sampling probability than others. It results in a biased sample [ 1 ] of a population (or non-human factors) in which all individuals, or instances, were not equally likely to have been selected ...

  6. Stratification (clinical trials) - Wikipedia

    en.wikipedia.org/wiki/Stratification_(clinical...

    Stratified purposive sampling is a type of typical case sampling, and is used to get a sample of cases that are "average", "above average", and "below average" on a particular variable; this approach generates three strata, or levels, each of which is relatively homogeneous, or alike. [1]

  7. Survey sampling - Wikipedia

    en.wikipedia.org/wiki/Survey_sampling

    This type of sampling is common in non-probability market research surveys. Convenience Samples: The sample is composed of whatever persons can be most easily accessed to fill out the survey. In non-probability samples the relationship between the target population and the survey sample is immeasurable and potential bias is unknowable.

  8. Snowball sampling - Wikipedia

    en.wikipedia.org/wiki/Snowball_sampling

    In sociology and statistics research, snowball sampling [1] (or chain sampling, chain-referral sampling, referral sampling [2] [3]) is a nonprobability sampling technique where existing study subjects recruit future subjects from among their acquaintances. Thus the sample group is said to grow like a rolling snowball.

  9. Stratified randomization - Wikipedia

    en.wikipedia.org/wiki/Stratified_randomization

    Graphic breakdown of stratified random sampling. In statistics, stratified randomization is a method of sampling which first stratifies the whole study population into subgroups with same attributes or characteristics, known as strata, then followed by simple random sampling from the stratified groups, where each element within the same subgroup are selected unbiasedly during any stage of the ...