probability

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Probability

The relative likelihood of a particular outcome among all possible outcomes.

probability

the likelihood of a particular uncertain event occurring, measured on a scale from 0.0 (such an event is impossible) to 1.0 (such an event is certain to occur). People generally estimate probabilities on the basis of the relative frequency with which an event has occurred in the past, under given circumstances, and generalize from this past experience. In some circumstances it is easy to estimate the proportion of occasions on which an event occurs; for example, the probability of getting ‘heads’ when flipping a balanced coin is 0.5 because with such a coin in the long run we would get 50% ‘heads’ and 50% ‘tails’. In estimating probabilities in business situations, though, there may be no or only a few previous experiences that can be used to gauge the relative frequency of an event occurring. See also RISK AND UNCERTAINTY.
References in periodicals archive ?
But mounting evidence (the recent admissions of cyclist Lance Armstrong (2), the words of cyclist Floyd Landis (3), and the US government's Mitchell report (4) on baseball doping, to name a few sources) indicates that the pretest probability of doping, at least in some sports, is very high.
Tool for estimating pretest probability of coronary heart disease Variable Score Example: 52- year-old woman Age (male/female): -Under 40/under 50 3 -40 to 50/50 to 64 6 6 -55 or older/65 or older 9 Estrogen status positive (F) -3 -3 Estrogen status negative (F) 3 Angina history typical * 5 Angina history atypical 3 Angina history nonanginal 1 1 Diabetes 2 2 Hyperlipidemia 1 1 Hypertension 1 Smoking (any) 1 First-degree family history 1 1 of coronary artery disease Obesity (BMI >27 kg/[m.
Bayes' theorem indicates that the post-test probability of a patient having CAD is based upon pretest probability and test accuracy (Figure 2).
Value of assessment of the pretest probability of deep vein thrombosis in clinical management.
Indeed, in these neoplasms the pretest probability provided by the clinical data is often more helpful than the results of immunostaining and other information provided by ancillary tests.
Besides the pretest probability (PTP), the value of electrocardiographic exercise test depends on the ability to do bicycle exercise testing and to reach submaximal exercise heart rate.
Third, even if genetic similarity could be precisely defined, the relationship between the degree of genetic similarity and the probability of point-source spread is unknown and doubtless varies in relation to pretest probability, depending on the epidemiologic context (e.
However, as is true for any imperfect test, the pretest probability of rheumatic disease dramatically affects the predictive value of tests intended to identify them.
This would increase the pretest probability of the impairment and consequently increase the protective value derived from changes to the underwriting requirements tailored to detect that impairment.
4) Note that Patient 2 has the same post-test probability that was estimated using the positive predictive value (accounting for rounding error), because he was assigned a pretest probability equal to the population prevalence.
In this study, we found the pretest probability (prevalence) of hypomobility to be 28% of segments tested, and 44% of individuals.