Statistical hypothesis test: Difference between revisions

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{{main|Lady tasting tea}}

In a famous example of hypothesis testing, known as the ''Lady tasting tea'',<ref name=fisher>{{cite book|first=Sir Ronald A.|last=Fisher|author-link=Ronald Fisher|chapter=Mathematics of a Lady Tasting Tea|orig-year=1935|year=1956|title=The World of Mathematics, volume 3|editor=James Roy Newman|chapter-url=https://books.google.com/books?id=oKZwtLQTmNAC&q=%22mathematics+of+a+lady+tasting+tea%22&pg=PA1512|trans-title=Design of Experiments|publisher=Courier Dover Publications|isbn=978-0-486-41151-4}} Originally from Fisher's book ''Design of Experiments''.</ref> Dr. [[Muriel Bristol]], a female colleague of Fisher claimed to be able to tell whether the tea or the milk was added first to a cup. Fisher proposed to give her eight cups, four of each variety, in random order. One could then ask what the probability was for her getting the number she got correct, but just by chance. The null hypothesis was that the Lady had no such ability. The test statistic was a simple count of the number of successes in selecting the 4 cups. The critical region was the single case of 4 successes of 4 possible based on a conventional probability criterion (<&nbsp;5%). A pattern of 4 successes corresponds to 1 out of 70 possible combinations (p≈&nbsp;1.4%). Fisher asserted that no alternative hypothesis was (ever) required. The lady correctly identified every cup,<ref>{{cite book|last=Box|first=Joan Fisher|title=R.A. Fisher, The Life of a Scientist|year=1978|___location=New York|publisher=Wiley|page=134|isbn=978-0-471-09300-8}}</ref> which would be considered a statistically significant result.

===Courtroom trial===