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  2. Homogeneity and heterogeneity (statistics) - Wikipedia

    en.wikipedia.org/wiki/Homogeneity_and...

    They relate to the validity of the often convenient assumption that the statistical properties of any one part of an overall dataset are the same as any other part. In meta-analysis, which combines the data from several studies, homogeneity measures the differences or similarities between the several studies (see also Study heterogeneity).

  3. Oversampling and undersampling in data analysis - Wikipedia

    en.wikipedia.org/wiki/Oversampling_and_under...

    The answer is no. Class imbalance is not a problem in itself at all. Additionally, oversampling; undersampling; as well as assigning weights to samples; may be applied by practitioners in multi-class classification or situations with very imbalanced cost structure. This might be done in order to achieve "desireable", best performances for each ...

  4. Study heterogeneity - Wikipedia

    en.wikipedia.org/wiki/Study_heterogeneity

    Statistical testing for a non-zero heterogeneity variance is often done based on Cochran's Q [13] or related test procedures. This common procedure however is questionable for several reasons, namely, the low power of such tests [14] especially in the very common case of only few estimates being combined in the analysis, [15] [7] as well as the specification of homogeneity as the null ...

  5. Homogeneity and heterogeneity - Wikipedia

    en.wikipedia.org/wiki/Homogeneity_and_heterogeneity

    Homogeneity and heterogeneity; only ' b ' is homogeneous Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image.A homogeneous feature is uniform in composition or character (i.e., color, shape, size, weight, height, distribution, texture, language, income, disease, temperature, radioactivity, architectural design, etc.); one that is heterogeneous ...

  6. Ontology-based data integration - Wikipedia

    en.wikipedia.org/wiki/Ontology-based_data...

    Schematic heterogeneity that particularly appears in structured databases is also an aspect of structural heterogeneity. [3] Semantic heterogeneity: differences in interpretation of the 'meaning' of data are source of semantic heterogeneity; System heterogeneity: use of different operating system, hardware platforms lead to system heterogeneity

  7. Post hoc analysis - Wikipedia

    en.wikipedia.org/wiki/Post_hoc_analysis

    In a scientific study, post hoc analysis (from Latin post hoc, "after this") consists of statistical analyses that were specified after the data were seen. [1] [2] They are usually used to uncover specific differences between three or more group means when an analysis of variance (ANOVA) test is significant. [3]

  8. Endogeneity (econometrics) - Wikipedia

    en.wikipedia.org/wiki/Endogeneity_(econometrics)

    The endogeneity problem is particularly relevant in the context of time series analysis of causal processes. It is common for some factors within a causal system to be dependent for their value in period t on the values of other factors in the causal system in period t − 1.

  9. Latent class model - Wikipedia

    en.wikipedia.org/wiki/Latent_class_model

    In statistics, a latent class model (LCM) is a model for clustering multivariate discrete data. It assumes that the data arise from a mixture of discrete distributions, within each of which the variables are independent. It is called a latent class model because the class to which each data point belongs is unobserved, or latent.