Dear Andreea,
the following articles might be of some interest (please, see www.bmj.com):
J Martin Bland and Douglas G Altman. Statistics Notes: Transforming data.
BMJ 1996;312;770;
J Martin Bland and Douglas G Altman. Statistics notes: Transformations,
means,and confidence intervals. BMJ 1996;312;1079
J Martin Bland and Douglas G Altman. Statistics Notes: The use of
transformation. BMJ 1996;312;1153.
Kind Regards,
Carlo
-----Messaggio originale-----
Da: [email protected]
[mailto:[email protected]] Per conto di Andreea Cristiana
Didilescu
Inviato: venerdì 15 gennaio 2010 8.54
A: [email protected]
Oggetto: st: data transformation - need help
Hello,
Could anyone help me with some data transformations? I have two
samples (n=45) with skewed distribution. After using ladder command,
it came out that square transformation would be suitable for both of
them. May I perform a ttest after performing data transformation? How
should I deal with the results? Should I go back to the original data
(e.g. mean difference)? What about the p-value?
Thanks in advance,
Andreea
--
Andreea Didilescu, DDS, PhD
Senior Lecturer, Faculty of Dental Medicine
"Carol Davila" UMP, Bucharest, Romania
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