Hi all,
I want to state that although by simulation I showed that Paaveen's results
are plausible, I firmly believe that no statistical technique can produce
reliable results on the correlation based on a such a small sample size.
On Tue, Jul 31, 2018 at 6:04 AM, Martin Bland <
[log in to unmask]> wrote:
> I think that only more real observations could do this.
>
> Martin
>
> On 25 July 2018 at 11:50, Steve Nyangoma <[log in to unmask]> wrote:
>
> > Could resampling methods be used to generate more data to confirm
> > evidence?
> >
> > On Wed, Jul 25, 2018 at 10:08 AM Martin Bland <000017e8e212eb29-dmarc-
> > [log in to unmask]> wrote:
> >
> >> Non-parametric is useless here, as with fewer than 6 observations all
> >> possible values of either Spearman's or Kendall's have P>0.05.
> >>
> >> This is a case where the question of whether there is good evidence of a
> >> relationship between two variables with only 4 observations always has
> the
> >> answer "no, you would need more data."
> >>
> >> Martin
> >>
> >> On 25 July 2018 at 06:24, Juanita Hatcher <[log in to unmask]>
> >> wrote:
> >>
> >> > I agree. Non parametric may be better, but one is still very
> restricted
> >> by
> >> > a very small data set. Look at the data.
> >> >
> >> > Juanita Hatcher
> >> >
> >> > > On Jul 24, 2018, at 2:33 PM, Robert Newcombe <
> [log in to unmask]>
> >> > wrote:
> >> > >
> >> > > Exactly! The first step is to plot a scatter diagram. Also, on a
> >> dataset
> >> > as small as this, there is no real positive assurance that parametric
> >> > assumptions hold, and the correlation is particularly sensitive to
> >> > distributional assumptions. So I suggest a non-parametric correlation
> >> > rather than a parametric one anyway. With the proviso that this could
> >> well
> >> > be exactly 1, without this finding being anything to get excited
> about.
> >> > >
> >> > > Robert Newcombe.
> >> > >
> >> > >
> >> > > -----Original Message-----
> >> > > From: A UK-based worldwide e-mail broadcast system mailing list
> >> [mailto:
> >> > [log in to unmask]] On Behalf Of John Bibby
> >> > > Sent: 24 July 2018 21:28
> >> > > To: [log in to unmask]
> >> > > Subject: Re: correlation coefficient
> >> > >
> >> > > Please look at the data, not the summary statistics. JOHN BIBBY
> >> > >
> >> > > On Tue, 24 Jul 2018 at 20:01, Martin Bland < 000017e8e212eb29-dmarc-
> >> > [log in to unmask]> wrote:
> >> > >
> >> > >> You are correct, the value of the correlation coefficient which
> would
> >> > >> be significant with 4 observations is 0.95.
> >> > >>
> >> > >> Martin
> >> > >>
> >> > >> On 24 July 2018 at 17:57, paaveen jeyaganth <[log in to unmask]>
> >> wrote:
> >> > >>
> >> > >>> Dear allstat ,
> >> > >>> i have 4 data point i did a pearson correlation end up with r=
> >> > >>> 0.8919 p= 0.1081 why is that it's not significant since it's high
> >> > >>> correlation 0.89 because of sample size??
> >> > >>>
> >> > >>> Thanks
> >> > >>> Paaveen
> >> > >>>
> >> > >>> You may leave the list at any time by sending the command
> >> > >>>
> >> > >>> SIGNOFF allstat
> >> > >>>
> >> > >>> to [log in to unmask], leaving the subject line blank.
> >> > >>>
> >> > >>
> >> > >>
> >> > >>
> >> > >> --
> >> > >> ***************************************************
> >> > >> J. Martin Bland
> >> > >> Prof. of Health Statistics Emeritus
> >> > >> Dept. of Health Sciences
> >> > >> Seebohm Rowntree Building
> >> > >> University of York
> >> > >> Heslington
> >> > >> York YO10 5DD
> >> > >>
> >> > >> Email: [log in to unmask]
> >> > >> Phone: 01904 321334 Fax: 01904 321382
> >> > >> Web site: http://martinbland.co.uk/
> >> > >>
> >> > >> Statement by the University of York:
> >> > >> This email and its attachments may be confidential and are intended
> >> > >> solely for the use of the intended recipient. If you are not the
> >> > >> intended recipient of this email and its attachments, you must take
> >> no
> >> > >> action based upon them, nor must you copy or show them to anyone.
> >> > >> Please contact the sender if you believe you have received this
> email
> >> > >> in error. Any views or opinions expressed are solely those of the
> >> > >> author and do not necessarily represent those of The University of
> >> York.
> >> > >> ***************************************************
> >> > >>
> >> > >> You may leave the list at any time by sending the command
> >> > >>
> >> > >> SIGNOFF allstat
> >> > >>
> >> > >> to [log in to unmask], leaving the subject line blank.
> >> > >>
> >> > > --
> >> > > ===== *Emails are generally written in a personal capacity, not for
> >> any
> >> > particular organisation.* *York Bus Forum: * Please note the following
> >> > meetings, *all **in West Offices at 5.15 for
> >> > > 5.30pm:*
> >> > > *17 July: *Monthly meeting
> >> > > *18 September: *Open Public Meeting to discuss *our discussion paper
> >> > "Better than a Bus Station" which is here <
> http://www.yorkbusforum.org/
> >> > busstationreport>*.
> >> > > *19 September: "Have your say with Julian Sturdy MP". *
> >> > >
> >> > > We generally meet on the third Tuesday of each month.
> >> > > Please get your friends to join - it's only £5! Details of how to
> join
> >> > are here <https://www.yorkbusforum.org/join-us/>.
> >> > >
> >> > > You may leave the list at any time by sending the command
> >> > >
> >> > > SIGNOFF allstat
> >> > >
> >> > > to [log in to unmask], leaving the subject line blank.
> >> > >
> >> > > You may leave the list at any time by sending the command
> >> > >
> >> > > SIGNOFF allstat
> >> > >
> >> > > to [log in to unmask], leaving the subject line blank.
> >> > >
> >> >
> >> > You may leave the list at any time by sending the command
> >> >
> >> > SIGNOFF allstat
> >> >
> >> > to [log in to unmask], leaving the subject line blank.
> >> >
> >>
> >>
> >>
> >> --
> >> ***************************************************
> >> J. Martin Bland
> >> Prof. of Health Statistics Emeritus
> >> Dept. of Health Sciences
> >> Seebohm Rowntree Building
> >> University of York
> >> Heslington
> >> York YO10 5DD
> >>
> >> Email: [log in to unmask]
> >> Phone: 01904 321334 Fax: 01904 321382
> >> Web site: http://martinbland.co.uk/
> >>
> >> Statement by the University of York:
> >> This email and its attachments may be confidential and are intended
> solely
> >> for the use of the intended recipient. If you are not the intended
> >> recipient of this email and its attachments, you must take no action
> based
> >> upon them, nor must you copy or show them to anyone. Please contact the
> >> sender if you believe you have received this email in error. Any views
> or
> >> opinions expressed are solely those of the author and do not necessarily
> >> represent those of The University of York.
> >> ***************************************************
> >>
> >> You may leave the list at any time by sending the command
> >>
> >> SIGNOFF allstat
> >>
> >> to [log in to unmask], leaving the subject line blank.
> >>
> >
>
>
> --
> ***************************************************
> J. Martin Bland
> Prof. of Health Statistics Emeritus
> Dept. of Health Sciences
> Seebohm Rowntree Building
> University of York
> Heslington
> York YO10 5DD
>
> Email: [log in to unmask]
> Phone: 01904 321334 Fax: 01904 321382
> Web site: http://martinbland.co.uk/
>
> Statement by the University of York:
> This email and its attachments may be confidential and are intended solely
> for the use of the intended recipient. If you are not the intended
> recipient of this email and its attachments, you must take no action based
> upon them, nor must you copy or show them to anyone. Please contact the
> sender if you believe you have received this email in error. Any views or
> opinions expressed are solely those of the author and do not necessarily
> represent those of The University of York.
> ***************************************************
>
> You may leave the list at any time by sending the command
>
> SIGNOFF allstat
>
> to [log in to unmask], leaving the subject line blank.
>
You may leave the list at any time by sending the command
SIGNOFF allstat
to [log in to unmask], leaving the subject line blank.
|