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  2. 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 ...

  3. Bias (statistics) - Wikipedia

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

    This can also be termed selection effect, sampling bias and Berksonian bias. [3] Spectrum bias arises from evaluating diagnostic tests on biased patient samples, leading to an overestimate of the sensitivity and specificity of the test. For example, a high prevalence of disease in a study population increases positive predictive values, which ...

  4. Selection bias - Wikipedia

    en.wikipedia.org/wiki/Selection_bias

    Selection bias is the bias introduced by the selection of individuals, groups, or data for analysis in such a way that proper randomization is not achieved, thereby failing to ensure that the sample obtained is representative of the population intended to be analyzed. [1] It is sometimes referred to as the selection effect.

  5. Bias - Wikipedia

    en.wikipedia.org/wiki/Bias

    Media bias is the bias or perceived bias of journalists and news producers within the mass media in the selection of events, the stories that are reported, and how they are covered. The term generally implies a pervasive or widespread bias violating the standards of journalism , rather than the perspective of an individual journalist or article ...

  6. List of cognitive biases - Wikipedia

    en.wikipedia.org/wiki/List_of_cognitive_biases

    Egocentric bias is the tendency to rely too heavily on one's own perspective and/or have a different perception of oneself relative to others. [34] The following are forms of egocentric bias: Bias blind spot, the tendency to see oneself as less biased than other people, or to be able to identify more cognitive biases in others than in oneself. [35]

  7. Survey sampling - Wikipedia

    en.wikipedia.org/wiki/Survey_sampling

    Bias in surveys is undesirable, but often unavoidable. The major types of bias that may occur in the sampling process are: Non-response bias: When individuals or households selected in the survey sample cannot or will not complete the survey there is the potential for bias to result from this non-response. Nonresponse bias occurs when the ...

  8. Self-selection bias - Wikipedia

    en.wikipedia.org/wiki/Self-selection_bias

    In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with nonprobability sampling.It is commonly used to describe situations where the characteristics of the people which cause them to select themselves in the group create abnormal or undesirable conditions in the group.

  9. Unbiased estimation of standard deviation - Wikipedia

    en.wikipedia.org/wiki/Unbiased_estimation_of...

    Correction factor versus sample size n.. When the random variable is normally distributed, a minor correction exists to eliminate the bias.To derive the correction, note that for normally distributed X, Cochran's theorem implies that () / has a chi square distribution with degrees of freedom and thus its square root, / has a chi distribution with degrees of freedom.