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1 Studies in the History of Statistics and Probability ... - Sheynin, Oscar

1 Studies in the History of Statistics and Probability ... - Sheynin, Oscar

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The verification <strong>of</strong> <strong>the</strong> truth <strong>of</strong> a scientific proposition by practice,<strong>in</strong> <strong>the</strong> first place concern<strong>in</strong>g fundamental sciences, has a specialproperty, namely, that it <strong>of</strong>ten takes more than a generation.Consequently, at least because <strong>of</strong> this <strong>the</strong> transfer <strong>of</strong> <strong>in</strong>terest <strong>in</strong> sciencefrom one generation to <strong>the</strong> next one is essentially important.On <strong>the</strong> o<strong>the</strong>r h<strong>and</strong>, it is also important to br<strong>in</strong>g that generalpsychological arrangement <strong>in</strong> correspondence with <strong>the</strong> actual results.Such efforts are go<strong>in</strong>g on <strong>in</strong> all sciences under differ<strong>in</strong>g circumstances.In <strong>the</strong> <strong>the</strong>ory <strong>of</strong> probability <strong>the</strong> tension <strong>of</strong> passions is somewhatstronger than, say, <strong>in</strong> ma<strong>the</strong>matics as a whole: it is possibly partlyconnected with Laplace. He was at <strong>the</strong> source <strong>of</strong> modern probability<strong>and</strong> <strong>the</strong> literary merits <strong>of</strong> his contribution laid an excessive discrepancybetween its emotional <strong>and</strong> philosophical <strong>and</strong> its concrete scientificaspects.The too wide general hopes are characterized by <strong>the</strong> emotionalshortcom<strong>in</strong>g <strong>of</strong> chang<strong>in</strong>g <strong>in</strong>to disappo<strong>in</strong>tment once encounter<strong>in</strong>g a realproblem. In a purely scientific aspect it consists <strong>in</strong> that <strong>the</strong> researcher,when formulat<strong>in</strong>g new problems, is not sufficiently critical. As aresult, efforts <strong>and</strong> material values are spent on futile attempts to solveproblems whereas <strong>the</strong> impossibility <strong>of</strong> achiev<strong>in</strong>g this would be obvioushad he been a bit more critical.In any case, certa<strong>in</strong> ideas were be<strong>in</strong>g developed <strong>in</strong> scienceconcern<strong>in</strong>g <strong>the</strong> sphere <strong>of</strong> application <strong>of</strong> <strong>the</strong> stochastic methods.Actually, each scientist, who carried out some applied study <strong>in</strong>volv<strong>in</strong>gprobability <strong>the</strong>ory, made a certa<strong>in</strong> contribution to <strong>the</strong>se ideas.However, <strong>the</strong>ir clear formulation (brilliant also <strong>in</strong> <strong>the</strong> purely literarysense) is due to Mises (1928, p. 14). He himself also attempted toconstruct a peculiar ma<strong>the</strong>matical foundation <strong>of</strong> <strong>the</strong> <strong>the</strong>ory <strong>of</strong>probability which stirred up animated criticism <strong>and</strong> at present <strong>the</strong>generally recognized axiomatization <strong>of</strong> probability is that provided byKolmogorov (1933/1974). Never<strong>the</strong>less <strong>the</strong> concept itself <strong>of</strong> practicalapplication largely follows Mises’ idea.I rem<strong>in</strong>d briefly this concept <strong>of</strong> statistical homogeneity or statisticalensemble (collective). For ascerta<strong>in</strong><strong>in</strong>g <strong>the</strong> pr<strong>in</strong>ciples I restrict myattention to <strong>the</strong> most simple case when an experiment can ei<strong>the</strong>r leadto <strong>the</strong> occurrence <strong>of</strong> some event A or not. Denote by n A <strong>the</strong> number <strong>of</strong>its occurrences <strong>in</strong> n experiments repeated under presumably <strong>the</strong> sameconditions. The ratio n A /n is called <strong>the</strong> frequency <strong>of</strong> <strong>the</strong> occurrence <strong>of</strong>event A. Even before Mises statisticians (for example Poisson whostudied <strong>the</strong> probability <strong>of</strong> judicial verdicts) understood perfectly wellthat for <strong>the</strong> applicability <strong>of</strong> stochastic methods to study <strong>the</strong> event A <strong>the</strong>stability <strong>of</strong> <strong>the</strong> frequency n A /n as n <strong>in</strong>creases should experience everless fluctuations <strong>and</strong> tend, <strong>in</strong> some sense, to a limit (which is <strong>in</strong>deedunderstood as <strong>the</strong> probability P(A) <strong>of</strong> A).Mises supplemented <strong>the</strong>se ideas by a clear formulation <strong>of</strong> ano<strong>the</strong>rproperty that was also <strong>in</strong>tuitively perfectly well understood bystatisticians. Here it is. Separate <strong>the</strong> n trials beforeh<strong>and</strong> <strong>in</strong>tosufficiently large totalities n 1 , n 2 , ..., <strong>the</strong>n <strong>the</strong> respective frequenciesn A /n 1 , n A /n 2 , ... should also be close to each o<strong>the</strong>r. The separation oughtto be done by draw<strong>in</strong>g on <strong>the</strong> previous <strong>in</strong>formation; thus, two totalitiescould have been trials done <strong>in</strong> summer <strong>and</strong> w<strong>in</strong>ter with <strong>the</strong> frequencies93

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