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  2. Phi coefficient - Wikipedia

    en.wikipedia.org/wiki/Phi_coefficient

    In statistics, the phi coefficient (or mean square contingency coefficient and denoted by φ or r φ) is a measure of association for two binary variables.. In machine learning, it is known as the Matthews correlation coefficient (MCC) and used as a measure of the quality of binary (two-class) classifications, introduced by biochemist Brian W. Matthews in 1975.

  3. Contingency table - Wikipedia

    en.wikipedia.org/wiki/Contingency_table

    In statistics, a contingency table ... A simple measure, applicable only to the case of 2 × 2 contingency tables, is the phi coefficient (φ) defined by

  4. Cramér's V - Wikipedia

    en.wikipedia.org/wiki/Cramér's_V

    In statistics, Cramér's V (sometimes referred to as Cramér's phi and denoted as φ c) is a measure of association between two nominal variables, giving a value between 0 and +1 (inclusive). It is based on Pearson's chi-squared statistic and was published by Harald Cramér in 1946.

  5. Effect size - Wikipedia

    en.wikipedia.org/wiki/Effect_size

    In statistics, an effect size is a value measuring the strength of the relationship between two variables in a population, or a sample-based estimate of that quantity. It can refer to the value of a statistic calculated from a sample of data, the value of one parameter for a hypothetical population, or to the equation that operationalizes how statistics or parameters lead to the effect size ...

  6. Standard normal table - Wikipedia

    en.wikipedia.org/wiki/Standard_normal_table

    Example: To find 0.69, one would look down the rows to find 0.6 and then across the columns to 0.09 which would yield a probability of 0.25490 for a cumulative from mean table or 0.75490 from a cumulative table. To find a negative value such as -0.83, one could use a cumulative table for negative z-values [3] which yield a probability of 0.20327.

  7. List of common physics notations - Wikipedia

    en.wikipedia.org/wiki/List_of_common_physics...

    coefficient of friction: unitless (dynamic) viscosity (also ) pascal second (Pa⋅s) permeability (electromagnetism) henry per meter (H/m) reduced mass: kilogram (kg) Standard gravitational parameter: cubic meter per second squared mu nought Vacuum permeability or the magnetic constant

  8. Evaluation of binary classifiers - Wikipedia

    en.wikipedia.org/wiki/Evaluation_of_binary...

    Instead, measures such as the phi coefficient, Matthews correlation coefficient, informedness or Cohen's kappa may be preferable to assess the performance of a binary classifier. [10] [11] As a correlation coefficient, the Matthews correlation coefficient is the geometric mean of the regression coefficients of the problem and its dual.

  9. Golden ratio - Wikipedia

    en.wikipedia.org/wiki/Golden_ratio

    where the Greek letter phi (⁠ ⁠ or ⁠ ⁠) denotes the golden ratio. [ a ] The constant ⁠ φ {\displaystyle \varphi } ⁠ satisfies the quadratic equation ⁠ φ 2 = φ + 1 {\displaystyle \textstyle \varphi ^{2}=\varphi +1} ⁠ and is an irrational number with a value of [ 1 ]