JiscMail Logo
Email discussion lists for the UK Education and Research communities

Help for ALLSTAT Archives


ALLSTAT Archives

ALLSTAT Archives


allstat@JISCMAIL.AC.UK


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ALLSTAT Home

ALLSTAT Home

ALLSTAT  August 2009

ALLSTAT August 2009

Options

Subscribe or Unsubscribe

Subscribe or Unsubscribe

Log In

Log In

Get Password

Get Password

Subject:

update: t test: "must make n1, n2 equal at all costs" -- does not make sense, right? -- so true.

From:

dr kardos laszlo <[log in to unmask]>

Reply-To:

dr kardos laszlo <[log in to unmask]>

Date:

Tue, 11 Aug 2009 10:49:52 +0200

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (60 lines)

for those who remember/are interested in this issue from back in june.

first and foremost: let me thank the community, especially the almost 30 
individuals who replied, for all the support and expert advice sent to 
me. the opinion that no data should be thrown away was unanimous, as i 
kind of expected.

i wrote the rebuttal and just got word that the journal has accepted the 
manuscript for publication.

note to jamie and adam: next season, please declare the myth that the 
reviewer is always right busted. let the world know.


dr kardos laszlo wrote:
> dear list members,
>
> i would be grateful for opinion from the statistical community on an 
> issue i first thought trivial, but later... here it goes:
>
> we recruited n1 = 200 patients of a disease and n2 = 380 healthy 
> controls to compare them in terms of some outcome using t tests.
>
> as part of a publication process in a reputable journal which shall 
> remain unnamed, a reviewer complained that this setting is unbalanced; 
> n1 should be equal to n2.
>
> assuming that the reviewer wants to see the principle "50-50% split 
> gives greatest power" upheld, we explained in a rebuttal that n1 was 
> limited by factors beyond our control, while n2 was not, so the choice 
> was either to limit n2 (and the test's power) artificially to ensure 
> balance or to put allocated study resources to good use and recruit 
> more controls and, with them, extra power and precision for our analysis.
>
> they still, however, insist that balance is all crucial. clearly, we 
> cannot now (and could not have at design time) set n1 = n2 = 290. the 
> only way we could satisfy them would be by throwing away a random 180 
> extra controls and re-analyzing with n1 = n2 = 200.
>
> my key question: could the reviewer be right on this? are there any 
> circumstances under which the trade-off bottom line between a 
> full-balance, lower power and a broken-balance, higher power approach 
> favors the former, if these are the only two options? if not, are 
> there any literature sources (or word from high-up stats experts) 
> explicitly clarifying this issue, something we can refer to rather 
> than expect them to take our word for it?
>
>
> on a more general note, what is the current common wisdom on how to 
> handle disagreements with peer reviewers on strictly statistical 
> issues? i hear "the reviewer is always right" from time to time, but 
> then find myself feeling uncomfortable when this happens to go 
> directly counter even to the very basics of my med stats education.
>
> best regards,
>
> laszlo
>
>

Top of Message | Previous Page | Permalink

JiscMail Tools


RSS Feeds and Sharing


Advanced Options


Archives

March 2024
February 2024
January 2024
December 2023
November 2023
October 2023
September 2023
August 2023
July 2023
June 2023
May 2023
April 2023
March 2023
February 2023
January 2023
December 2022
November 2022
October 2022
September 2022
August 2022
July 2022
June 2022
May 2022
April 2022
March 2022
February 2022
January 2022
December 2021
November 2021
October 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
2006
2005
2004
2003
2002
2001
2000
1999
1998


JiscMail is a Jisc service.

View our service policies at https://www.jiscmail.ac.uk/policyandsecurity/ and Jisc's privacy policy at https://www.jisc.ac.uk/website/privacy-notice

For help and support help@jisc.ac.uk

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager