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  2. Compositional data - Wikipedia

    en.wikipedia.org/wiki/Compositional_data

    In statistics, compositional data are quantitative descriptions of the parts of some whole, conveying relative information. Mathematically, compositional data is represented by points on a simplex .

  3. Likelihood-ratio test - Wikipedia

    en.wikipedia.org/wiki/Likelihood-ratio_test

    In statistics, the likelihood-ratio test is a hypothesis test that involves comparing the goodness of fit of two competing statistical models, typically one found by maximization over the entire parameter space and another found after imposing some constraint, based on the ratio of their likelihoods.

  4. G-test - Wikipedia

    en.wikipedia.org/wiki/G-test

    We can derive the value of the G-test from the log-likelihood ratio test where the underlying model is a multinomial model. Suppose we had a sample x = ( x 1 , … , x m ) {\textstyle x=(x_{1},\ldots ,x_{m})} where each x i {\textstyle x_{i}} is the number of times that an object of type i {\textstyle i} was observed.

  5. Likelihood ratios in diagnostic testing - Wikipedia

    en.wikipedia.org/wiki/Likelihood_ratios_in...

    Likelihood Ratio: An example "test" is that the physical exam finding of bulging flanks has a positive likelihood ratio of 2.0 for ascites. Estimated change in probability: Based on table above, a likelihood ratio of 2.0 corresponds to an approximately +15% increase in probability.

  6. Sludge volume index - Wikipedia

    en.wikipedia.org/wiki/Sludge_volume_index

    Sludge Volume Index (SVI) is a process control parameter used to describe the settling characteristics of sludge in the aeration tank of an activated sludge process. [1] It was introduced by Mohlman in 1934 and has become one of the standard measures of the physical characteristics of activated sludge processes.

  7. Wilks's lambda distribution - Wikipedia

    en.wikipedia.org/wiki/Wilks's_lambda_distribution

    In statistics, Wilks' lambda distribution (named for Samuel S. Wilks), is a probability distribution used in multivariate hypothesis testing, especially with regard to the likelihood-ratio test and multivariate analysis of variance (MANOVA).

  8. Wald test - Wikipedia

    en.wikipedia.org/wiki/Wald_test

    There are several reasons to prefer the likelihood ratio test or the Lagrange multiplier to the Wald test: [18] [19] [20] Non-invariance: As argued above, the Wald test is not invariant under reparametrization, while the likelihood ratio tests will give exactly the same answer whether we work with R, log R or any other monotonic transformation ...

  9. Levene's test - Wikipedia

    en.wikipedia.org/wiki/Levene's_test

    The Brown–Forsythe test uses the median instead of the mean in computing the spread within each group (¯ vs. ~, above).Although the optimal choice depends on the underlying distribution, the definition based on the median is recommended as the choice that provides good robustness against many types of non-normal data while retaining good statistical power. [3]