Odds ratio
An odds ratio is the ratio of the odds of an outcome under one condition or in one group to the odds under another condition or in another group.
Statistics Slam Dunk
An odds ratio is the ratio of the odds of an event under one condition to the odds of the event under another condition.
- How it is used
- Interprets binary-outcome logistic regression by translating coefficients among probabilities, odds ratios, and log odds.
- How deep it goes
- Defines the three scales, works through conversions, and applies them to a regression coefficient without developing the underlying estimation mathematics.
- Examples
- Uses an on-time flight calculation and an NBA playoff logistic regression with R conversion commands.
- What you can do after
- Apply R functions such as exp() and plogis() to convert logistic-regression results into interpretable probabilities.
Grokking Statistics
An odds ratio is the quotient of two odds, measuring how the relative likelihood of an event changes between conditions.
- How it is used
- Uses odds ratios to compare event risk across conditions and interpret logistic-regression changes per unit of x.
- How deep it goes
- Explains probability-to-odds conversion, log-odds, and Python comparison, stopping short of a formal derivation.
- Examples
- Uses toddler-meltdown risk at four versus six hours, with logistic probabilities, odds, and Python calculations.
- What you can do after
- Apply it via Python to convert predicted probabilities into odds and compare odds between two conditions.
Related concepts
- logistic regressionmeasured by · Logistic regression is a statistical classification model that estimates categorical outcome probabilities by applying a logistic or softmax function to a linear combination of input features.
- oddsmeasures · Odds are the ratio of the probability of an event occurring to the probability of its complement.
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