enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 68–95–99.7 rule - Wikipedia

    en.wikipedia.org/wiki/68–95–99.7_rule

    In statistics, the 68–95–99.7 rule, also known as the empirical rule, and sometimes abbreviated 3sr or 3 σ, is a shorthand used to remember the percentage of values that lie within an interval estimate in a normal distribution: approximately 68%, 95%, and 99.7% of the values lie within one, two, and three standard deviations of the mean ...

  3. Rule of three (statistics) - Wikipedia

    en.wikipedia.org/wiki/Rule_of_three_(statistics)

    The rule can then be derived [2] either from the Poisson approximation to the binomial distribution, or from the formula (1−p) n for the probability of zero events in the binomial distribution. In the latter case, the edge of the confidence interval is given by Pr(X = 0) = 0.05 and hence (1−p) n = .05 so n ln(1–p) = ln .05 ≈ −2

  4. Secretary problem - Wikipedia

    en.wikipedia.org/wiki/Secretary_problem

    The cutoff rule (CR): Do not accept any of the first y applicants; thereafter, select the first encountered candidate (i.e., an applicant with relative rank 1). This rule has as a special case the optimal policy for the classical secretary problem for which y = r. Candidate count rule (CCR): Select the y-th encountered candidate. Note, that ...

  5. Scoring rule - Wikipedia

    en.wikipedia.org/wiki/Scoring_rule

    The classification accuracy score (percent classified correctly), a single-threshold scoring rule which is zero or one depending on whether the predicted probability is on the appropriate side of 0.5, is a proper scoring rule but not a strictly proper scoring rule because it is optimized (in expectation) not only by predicting the true ...

  6. p-value - Wikipedia

    en.wikipedia.org/wiki/P-value

    In his highly influential book Statistical Methods for Research Workers (1925), Fisher proposed the level p = 0.05, or a 1 in 20 chance of being exceeded by chance, as a limit for statistical significance, and applied this to a normal distribution (as a two-tailed test), thus yielding the rule of two standard deviations (on a normal ...

  7. Conditional entropy - Wikipedia

    en.wikipedia.org/wiki/Conditional_entropy

    where and denote the support sets of and .. Note: Here, the convention is that the expression ⁡ should be treated as being equal to zero. This is because ...

  8. Statistical significance - Wikipedia

    en.wikipedia.org/wiki/Statistical_significance

    [41] [42] For instance, the certainty of the Higgs boson particle's existence was based on the 5σ criterion, which corresponds to a p-value of about 1 in 3.5 million. [ 42 ] [ 43 ] In other fields of scientific research such as genome-wide association studies , significance levels as low as 5 × 10 −8 are not uncommon [ 44 ] [ 45 ] —as the ...

  9. Null hypothesis - Wikipedia

    en.wikipedia.org/wiki/Null_hypothesis

    Confirming the null hypothesis two-sided would amount to positively proving it is bigger or equal than 0 and to positively proving it is smaller or equal than 0; this is something for which infinite accuracy is needed as well as exactly zero effect, neither of which normally are realistic. Also measurements will never indicate a non-zero ...