[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: [OASIS Issue Tracker] Commented: (OFFICE-2228) FTEST: does it testthe variances, or whether two datasets come from the same population? Is it2-tailed?
[ http://tools.oasis-open.org/issues/browse/OFFICE-2228?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16695#action_16695 ] Andreas Guelzow commented on OFFICE-2228: ------------------------------------------ The standard F-Test tests the equality of the variances for two normally distributed population. It does not (and cannot) test equality of the distributions since it completely ignores the means. I will try to get hold of a machine with Excel to confirm what it is really doing. (After having taught statistics for close to 20 years I ought to be able to figure that out.) > FTEST: does it test the variances, or whether two datasets come from the same population? Is it 2-tailed? > --------------------------------------------------------------------------------------------------------- > > Key: OFFICE-2228 > URL: http://tools.oasis-open.org/issues/browse/OFFICE-2228 > Project: OASIS Open Document Format for Office Applications (OpenDocument) TC > Issue Type: Sub-task > Components: OpenFormula > Affects Versions: ODF 1.2 > Reporter: Eike Rathke > Assignee: Andreas Guelzow > Fix For: ODF 1.2 > > > Broken out from OFFICE-916 > FTEST > - "Summary: Returns the result of an F test (the probability that two datasets > have come from the same total population)" > Excel says it tests the probability that the *variances* are not > significantly different (which is not the same as coming from the same total > population). > [ed:] TODO: who can provide insight? > - "An F-test returns the one-tailed probability" Excel currently describes > this as the 2-tailed probability. I believe that is correct (see > http://www.coventry.ac.uk/ec/~nhunt/pottel.pdf). Old versions of Excel eg 97 > describe it as one tailed. It would be worth someone with real knowledge > checking this out. > [ed:] TODO: who can provide insight? -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://tools.oasis-open.org/issues/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]