odds

(noun)

the ratio of the probabilities of an event happening to that of it not happening

Related Terms

  • logarithm

Examples of odds in the following topics:

  • Odds Ratios

    • An odds ratio is the ratio of two odds.
    • In order to compute the odds ratio, one follows three steps:
    • Divide the first odds by the second odds to obtain the odds ratio.
    • The odds of a man drinking wine are $90$ to $10$ (or $9:1$) while the odds of a woman drinking wine are only $20$ to $80$ (or $1:4=0.25:1$).
    • The log odds ratio shown here is based on the odds for the event occurring in group $B$ relative to the odds for the event occurring in group $A$.
  • Optional Collaborative Classroom Activity

    • Look in the sports section of a newspaper or on the Internet for some sports data (baseball averages, basketball scores, golf tournament scores, football odds, swimming times, etc.).
  • Proportions

    • A third commonly used measure is the "odds ratio. " For our example, the odds of being healthy on the Mediterranean diet are 90:10 = 9:1; the odds on the AHA diet are 79:21 = 3.76:1.
    • The ratio of these two odds is 9/3.76 = 2.39.
    • Therefore, the odds of being healthy on the Mediterranean diet is 2.39 times the odds of being healthy on the AHA diet.
    • Note that the odds ratio is the ratio of the odds and not the ratio of the probabilities.
  • The Collins Case

    • The basic fallacy results from misunderstanding conditional probability, and neglecting the prior odds of a defendant being guilty before that evidence was introduced.
    • However, if the DNA evidence is the sole evidence against the accused, and the accused was picked out of a large database of DNA profiles, then the odds of the match being made at random may be reduced.
    • The odds in this scenario do not relate to the odds of being guilty; they relate to the odds of being picked at random.
  • Bayes' Rule

    • Bayes' rule relates the odds of event $A_1$ to event $A_2$, before (prior to) and after (posterior to) conditioning on another event $B$.
    • The odds on $A_1$ to event $A_2$ is simply the ratio of the probabilities of the two events.
    • More specifically, given events $A_1$, $A_2$ and $B$, Bayes' rule states that the conditional odds of $A_1:A_2$ given $B$ are equal to the marginal odds $A_1:A_2$ multiplied by the Bayes factor or likelihood ratio.
  • Evaluating the Normal approximation exercises

  • Statistical Literacy

    • This is called the "relative risk reduction. " The article does not provide information necessary to compute the absolute risk reduction, the odds ratio, or the number needed to treat.
  • Exercises

  • Introduction

    • Whenever you weigh the odds of whether or not to do your homework or to study for an exam, you are using probability.
  • Additional Properties of the Binomial Distribution

    • The median is unique and equal to $m = round(np)$ in cases where either $p \leq 1 \ln 2$ or $p \geq \ln 2$ or $|m np| \leq \min{(p, 1 p)}$ (except for the case when $p = \frac{1}{2}$ and n is odd).
    • When$p = \frac{1}{2}$ and n is odd, any number m in the interval $\frac{1}{2} \cdot (n 1) \leq m \leq \frac{1}{2} \cdot (n + 1)$ is a median of the binomial distribution.
Subjects
  • Accounting
  • Algebra
  • Art History
  • Biology
  • Business
  • Calculus
  • Chemistry
  • Communications
  • Economics
  • Finance
  • Management
  • Marketing
  • Microbiology
  • Physics
  • Physiology
  • Political Science
  • Psychology
  • Sociology
  • Statistics
  • U.S. History
  • World History
  • Writing

Except where noted, content and user contributions on this site are licensed under CC BY-SA 4.0 with attribution required.