Biology-Online • View topic - what is the t-test?

Join for Free!
122492 members

what is the t-test?

Debate and discussion of any biological questions not pertaining to a particular topic.

Moderator: BioTeam

what is the t-test?

Postby komrade_leni » Wed Aug 24, 2005 5:21 pm

Could someone please explain to me what the t-test is?
Posts: 1
Joined: Wed Aug 24, 2005 5:17 pm

Postby Jelanen » Wed Aug 24, 2005 7:52 pm

"Student" (real name: W. S. Gossett [1876-1937]) developed statistical methods to solve problems stemming from his employment in a brewery. Student's t-test deals with the problems associated with inference based on "small" samples: the calculated mean (Xavg) and standard deviation (sdev) may by chance deviate from the "real" mean and standard deviation (i.e., what you'd measure if you had many more data items: a "large" sample). For example, it it likely that the true mean size of maple leaves is "close" to the mean calculated from a sample of N randomly collected leaves. If N=5, 95% of the time the actual mean would be in the range: Xavg± 2.776 sdev/N1/2 ; if N=10: Xavg± 2.262 sdev/N1/2 ; if N=20: Xavg± 2.093 sdev/N1/2 ; if N=40; Xavg± 2.023 sdev/N1/2 ; and for "large" N: Xavg± 1.960 sdev/N1/2 . (These "small-sample" corrections are included in the descriptive statics report of the 95% confidence interval.)

Google is your friend.

'It is futile to pretend to the public that we understand how an amoeba evolved into a man, when we cannot tell our students how a human egg produces a skin cell or a brain cell!'

Dr Jérôme J. Lejeune
Inland Taipan
Inland Taipan
Posts: 218
Joined: Fri Mar 04, 2005 1:00 am
Location: The Lab

Postby sdekivit » Wed Aug 24, 2005 8:03 pm

a student's t-test is a statistical test to test the statistical significance of the differenece between two means or correlation.
King Cobra
King Cobra
Posts: 586
Joined: Sat Jul 30, 2005 7:16 pm
Location: holland

Return to General Discussion

Who is online

Users browsing this forum: No registered users and 0 guests