odds

(noun)

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

Related Terms

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 $A$.

  • Even and Odd Functions

    • Functions can be classified as "odd" or "even" based on their composition.
    • The terms "odd" and "even" can only be applied to a limited set of functions.
    • Oftentimes, the parity of a function will reveal whether it is odd or even.
    • How can we check if a function is odd or even?  
    • The function, $f(x)=x^3-4x$ is odd, since the graph is symmetric about the origin.  

  • Trigonometric Symmetry Identities

    • We have previously discussed even and odd functions.
    • On the other hand, sine and tangent are odd functions because they are symmetric about the origin.
    • Graphs that are symmetric about the origin represent odd functions.
    • For odd functions, any two points with opposite $x$-values also have opposite $y$-values.
    • Sine, cosecant, tangent, and cotangent are odd functions, and are symmetric around the origin.

  • Psychological Pricing

    • Another manifestation of the psychological aspects of pricing is the use of odd prices.
    • We call prices that end in such digits as 5, 7, 8, and 9 "odd prices. " Examples of odd prices include: $2.95, $15.98, or $299.99 .
    • For a long time, marketing people have attempted to explain why odd prices are used.
    • Odd prices, on the other hand, appear to represent bargains or savings and therefore encourage buying.
    • There seems to be some movement toward even pricing; however, odd pricing is still very common.

  • Nuclear Stability

    • Of the 254 known stable nuclides, only four have both an odd number of protons and an odd number of neutrons:
    • Also, only four naturally occurring, radioactive odd-odd nuclides have a half-life greater than a billion years:
    • Most odd-odd nuclei are highly unstable with respect to beta decay because the decay products are even-even and therefore more strongly bound, due to nuclear pairing effects.

  • The Even/Odd Strategy

    • Some projects use the parity of the minor number component to indicate the stability of the software: even means stable, odd means unstable.
    • The advantage of the even/odd system, which has been used by the Linux kernel project among others, is that it offers a way to release new functionality for testing without subjecting production users to potentially unstable code.
    • The development team handles the bug reports that come in from the unstable (odd-minor-numbered) series, and when things start to settle down after some number of micro releases in that series, they increment the minor number (thus making it even), reset the micro number back to "0", and release a presumably stable package.
    • The even/odd system is probably best for projects that have very long release cycles, and which by their nature have a high proportion of conservative users who value stability above new features.

  • Odd-Electron Molecules

    • Molecules with an odd number of electrons disobey the octet rule.
    • One class of such compounds are those that have an odd number of electrons.
    • As the octet rule requires eight electrons around each atom, a molecule with an odd number of electrons must disobey the octet rule.

  • 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.).

  • Characteristics of Mass Spectra

    • When a single electron is removed from a molecule to give an ion, the total electron count becomes an odd number, and we refer to such ions as radical cations.
    • A less common fragmentation, in which an even-electron neutral fragment is lost, produces an odd-electron radical cation fragment ion.
    • As a rule, odd-electron ions may fragment either to odd or even-electron ions, but even-electron ions fragment only to other even-electron ions.
    • Most of the fragment ions have odd-numbered masses, and therefore are even-electron cations.
    • Diethylmethylamine, on the other hand, has one nitrogen and its molecular mass (m/z = 87) is an odd number.

  • 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.