[R] suggestion for proportions
gunter.berton at gene.com
Wed Sep 7 16:47:00 CEST 2011
On Wed, Sep 7, 2011 at 7:28 AM, Viechtbauer Wolfgang (STAT)
<wolfgang.viechtbauer at maastrichtuniversity.nl> wrote:
> since it is paired data.
Actually, it is unclear to me from the OP's message whether this is the case.
In one sentence the OP says that the _number_ of samples is the same,
and in the next he says that "essentially" the samples are the same.
So, as usual, imprecision in the problem description leads to
imprecision in the solution.
But your point is well taken, of course.
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
>> On Behalf Of Bert Gunter
>> Sent: Wednesday, September 07, 2011 15:34
>> To: John Sorkin
>> Cc: r-help at r-project.org
>> Subject: Re: [R] suggestion for proportions
>> Please! ... ?prop.test
>> not t tests.
>> -- Bert
>> On Wed, Sep 7, 2011 at 4:21 AM, John Sorkin <JSorkin at grecc.umaryland.edu>
>> > >From you description, you should not used a paired Student's t-test.
>> One uses a paired test when pairs of observations come from the same
>> experimental unit (and thus are correlated). You describe a study where
>> each experimental unit is tested once and where there are two independent
>> groups of experimental units. Look at t.test (i.e. enter ?t.test).
>> > John
>> >>>> array chip <arrayprofile at yahoo.com> 9/7/2011 4:11 AM >>>
>> > Hi, I am wondering if anyone can suggest how to test the equality of 2
>> proportions. The caveat here is that the 2 proportions were calculated
>> from the same number of samples using 2 different tests. So essentially we
>> are comparing 2 accuracy rates from same, say 100, samples. I think this
>> is like a paired test, but don't know if really we need to consider the
>> "paired" nature of the data, and if yes then how? Or just use prop.test()
>> to compare 2 proportions?
>> > Any suggestion would be greatly appreciated.
>> > Thanks
>> > John
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