Free reference · 596 entries
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Short, plain definitions of the terms that turn up in statistics and data science — what they mean, and how they relate to each other. Nothing to sign in for.
12 of 596 entries under O
- Odds RatioP2/(1–P2) q = P1/(1–P1) . If P1 and P2 are equal, the odds ratio is equal to 1. If the symbols do not display properly, try the graphic version of this page
- Odds Ratio (Graphical)The odds ratio compares two probabilities (or proportions) P1 and P2 in the following way: If P1 and P2 are equal, the odds ratio is equal to 1.
- Omega-squareOmega-square is a synonym for the coefficient of determination.
- One-sided TestOne-sided test is a synonym for one-tailed test. See 2-Tailed vs. 1-Tailed Tests
- Order StatisticsThe order statistics of a random sample X1, X2, . . ., Xn are the sample values placed in ascending order.
- Ordered categorical dataCategorical variables are non-numeric “category” variables, e.g. color. Ordered categorical variables are category variables that have a quantitative dimension that can be ordered but is not on a regular scale.
- Ordinal ScaleAn ordinal scale is a measurement scale that assigns values to objects based on their ranking with respect to one another.
- Ordinary Least Squares RegressionOrdinary least squares regression is a special (and the most common) kind of ordinary linear regression.
- Ordinary Linear RegressionSee: simple linear regression
- Orthogonal Least SquaresIn ordinary least squares, we try to minimize the sum of the vertical squared distances between the observed points and the fitted line.
- Outcome variablesee dependent and independent variables
- OutlierSometimes a set of data will have one or more items with unusually large or unusually small values.
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