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prior probability

British  

noun

  1. statistics the probability assigned to a parameter or to an event in advance of any empirical evidence, often subjectively or on the assumption of the principle of indifference Compare posterior probability

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The predictive value of a laboratory test is based on “prior probability,” the likelihood that the patient has a disease before testing has been performed.

From Scientific American

“You just assign a prior probability to each of these models,” Kipping says.

From Scientific American

So each hypothesis gets a prior probability of one half, much as if one were to flip a coin to decide a wager.

From Scientific American

One fact is clear: if we assign a zero prior probability for such evidence coming our way, as some scientists did in the case of ‘Oumuamua by invoking the principle “it’s never aliens,” we will indeed never find any.

From Scientific American

The problem is that researchers usually have no way of knowing what the prior probability is.

From Nature