p = .000?

[SR Millis-3]

When SPSS output reports a p-value as .000, how should you report the value?

SR Millis

[Nissim Matatov]

Report what does it mean

On Wed, Jan 11, 2012 at 4:26 PM, SR Millis <[hidden email]> wrote:

When SPSS output reports a p-value as .000, how should you report the value?

SR Millis

[Mike]

If you follow APA style, use "p< .001".

-MIke Palij
New York University
[hidden email]

On Wed, Jan 11, 2012 at 9:26 AM, SR Millis <[hidden email]> wrote:

When SPSS output reports a p-value as .000, how should you report the value?

SR Millis

[lori.andersen]

as less than .001

On Wed, Jan 11, 2012 at 9:26 AM, SR Millis-3 [via SPSSX Discussion] <[hidden email]> wrote:

When SPSS output reports a p-value as .000, how should you report the value?

SR Millis

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[Poes, Matthew Joseph]

Ok first, I believe that there is nothing you can really do but to report it as you get it, or go against the APA recommendation, and report it as P<.001.

 

Second, let me say that I think the APA’s decision to require manuscripts reporting exact P values was a very dumb decision.  We should be going away from the attention to the exact P value, and more towards assessing significance of findings in terms of relative effect size.  In my opinion, the decision to require exact P values is just going to perpetuate misinterpretation of results as being “highly significant.”  Their decision was completely in contrast to the decisions made by other groups such as the What Works Clearinghouse in education.

 

Also note, that while sometimes you can double click on a value and get an exact value, I’ve tried this with P values, doesn’t appear to work for me with version 19, I just see a “0”.

 

Matthew J Poes

Research Data Specialist

Center for Prevention Research and Development

University of Illinois

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of SR Millis
Sent: Wednesday, January 11, 2012 8:26 AM
To: [hidden email]
Subject: p = .000?

 

When SPSS output reports a p-value as .000, how should you report the value?

 

SR Millis

 

[Julius Sim]

Hi,

The important thing is not to report it as 'p = .000', as this would
suggest that it is impossible to obtain the observed result (or a more
extreme one) if the null hypothesis were true, which makes no sense.

A p value given by SPSS as .000 means that the actual p value is less than
.0005 (otherwise it would have rounded to .001). So you can report it as
'p <.0005' (unless you don't want four decimal places, in which case just
give it as 'p <.001'). Make sure, though, that the way you present the p
value in terms of '<' does not cause it to be mistaken for the value of
alpha, which sometimes happens.

An analogous problem arises in the rare situations in which a p value is
given by SPSS as 'p = 1.000'. Consistency would suggest that this should
be reported as 'p >.999', as '1.000' makes no more sense than '.000'.

Best wishes,

Julius



> When SPSS  output reports a p-value as .000, how should you report the
> value?
>
> SR Millis
>

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[msherman]

Matthew: If you right click on the Table and then Open up the open to edit the table you will be able to click on Format and choose the number of decimal points from 0 to 36 places.  mfs

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Poes, Matthew Joseph
Sent: Wednesday, January 11, 2012 9:38 AM
To: [hidden email]
Subject: Re: p = .000?

 

Ok first, I believe that there is nothing you can really do but to report it as you get it, or go against the APA recommendation, and report it as P<.001.

 

Second, let me say that I think the APA’s decision to require manuscripts reporting exact P values was a very dumb decision.  We should be going away from the attention to the exact P value, and more towards assessing significance of findings in terms of relative effect size.  In my opinion, the decision to require exact P values is just going to perpetuate misinterpretation of results as being “highly significant.”  Their decision was completely in contrast to the decisions made by other groups such as the What Works Clearinghouse in education.

 

Also note, that while sometimes you can double click on a value and get an exact value, I’ve tried this with P values, doesn’t appear to work for me with version 19, I just see a “0”.

 

Matthew J Poes

Research Data Specialist

Center for Prevention Research and Development

University of Illinois

 

From: SPSSX(r) Discussion [hidden email] On Behalf Of SR Millis
Sent: Wednesday, January 11, 2012 8:26 AM
To: [hidden email]
Subject: p = .000?

 

When SPSS output reports a p-value as .000, how should you report the value?

 

SR Millis