Editing Probability interpretations (section)

==Subjectivism==
{{Main|Bayesian probability}}
Subjectivists, also known as '''Bayesians''' or followers of '''epistemic probability''', give the notion of probability a subjective status by regarding it as a measure of the 'degree of belief' of the individual assessing the uncertainty of a particular situation. [[Epistemic]] or subjective probability is sometimes called '''[[Credence (statistics)|credence]]''', as opposed to the term '''chance''' for a propensity probability. Some examples of epistemic probability are to assign a probability to the proposition that a proposed law of physics is true or to determine how probable it is that a suspect committed a crime, based on the evidence presented. The use of Bayesian probability raises the philosophical debate as to whether it can contribute valid [[theory of justification|justifications]] of [[belief]]. Bayesians point to the work of [[Frank P. Ramsey|Ramsey]]<ref name=ramsey /> (p 182) and [[Bruno de Finetti|de Finetti]]<ref name=deF /> (p 103) as proving that subjective beliefs must follow the [[laws of probability]] if they are to be coherent.<ref>{{cite book | last = Jaynes | first = E. T. | title = Probability theory the logic of science | publisher = Cambridge University Press | location = Cambridge, UK New York, NY | year = 2003 | isbn = 978-0521592710 }}</ref> Evidence casts doubt that humans will have coherent beliefs.<ref>{{cite book | last = Kahneman | first = Daniel | title = Thinking, fast and slow | publisher = Farrar, Straus and Giroux | location = New York | year = 2011 | isbn = 978-0374275631 }} The book contains numerous examples of the difference between idealized and actual thought. "[W]hen called upon to judge probability, people actually judge something else and believe they have judged probability." (p 98)</ref><ref>{{cite journal | last1 = Grove | first1 = William M. | last2 = Meehl | first2 = Paul E. | title = Comparative efficiency of informal (subjective, impressionistic) and formal (mechanical, algorithmic) prediction procedures: The clinical-statistical controversy | journal = Psychology, Public Policy, and Law | volume = 2 | issue = 2 | pages = 293–332 | year = 1996 | doi = 10.1037/1076-8971.2.2.293 | url = http://www.tc.umn.edu/~pemeehl/167GroveMeehlClinstix.pdf | url-status = dead | archive-url = https://web.archive.org/web/20111030214359/http://www.tc.umn.edu/~pemeehl/167GroveMeehlClinstix.pdf | archive-date = 30 October 2011 | df = dmy-all | citeseerx = 10.1.1.471.592 }} Statistical decisions are consistently superior to the subjective decisions of experts.</ref> The use of Bayesian probability involves specifying a [[prior probability]]. This may be obtained from consideration of whether the required prior probability is greater or lesser than a reference probability{{Clarify|date=April 2010}} associated with an [[urn model]] or a [[thought experiment]]. The issue is that for a given problem, multiple thought experiments could apply, and choosing one is a matter of judgement: different people may assign different prior probabilities, known as the [[reference class problem]]. The "[[sunrise problem]]" provides an example.