# What Does the t in t-test Stand For?

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- This topic has 5 replies, 3 voices, and was last updated 8 years, 1 month ago by dan weigel.

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- May 15, 2012 at 8:40 am #54060

dan weigelParticipant@weigel**Include @weigel in your post and this person will**

be notified via email.What does the t in t-test stand for?

0May 15, 2012 at 12:50 pm #193342

Robert ButlerParticipant@rbutler**Include @rbutler in your post and this person will**

be notified via email.Nothing – Fisher chose the letter “t” just as a simple way to refer to Gosset’s Student distribution.

“In his 1908 paper, “The Probable Error of a Mean”, Biometrika, 6, 1-25 Gosset introduced the statistic, z, for testing hypotheses on the mean of the normal distribution. Gosset used the divisor n, not the modern (n – 1), when he estimated and his z is proportional to the modern t with t = z sqrt (n – 1). Fisher introduced the t form because it fitted in with his theory of degrees of freedom (q.v.). Fisher used the t symbol and described Student’s distribution (and others based on the normal distribution) and the role of degrees of freedom in “On a Distribution Yielding the Error Functions of Several well Known Statistics”, Proceedings of the International Congress of Mathematics, Toronto, 2, 805-813. Although the paper was presented in 1924, it was not published until 1928 (Tankard, page 103; David, 1995). According to the OED2, the letter t was chosen arbitrarily. A new symbol suited Fisher for he was already using z for a statistic of his own (see entry for F).”

0May 17, 2012 at 3:21 pm #193358

Robert ButlerParticipant@rbutler**Include @rbutler in your post and this person will**

be notified via email.I’m not trying to be rude but I would like to ask you why you keep bumping your post to the top of the list? If you are hoping for a different answer I’m afraid you won’t get one. The answer I provided is a direct quote from a history text.

0May 17, 2012 at 4:22 pm #193359

Katie BarryKeymaster@KatieBarry**Include @KatieBarry in your post and this person will**

be notified via email.@rbutler – That’s me. I changed the title once and then recategorized the discussion so it wasn’t in “Welcome.” Sorry for the confusion.

0May 17, 2012 at 5:16 pm #193360

Robert ButlerParticipant@rbutler**Include @rbutler in your post and this person will**

be notified via email.Ok, thanks Katie – sorry about that Dan

0May 19, 2012 at 3:26 pm #193366

dan weigelParticipant@weigel**Include @weigel in your post and this person will**

be notified via email.Thanks

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