[R] Issue with t.test

Greg Snow 538280 @end|ng |rom gm@||@com
Tue Mar 12 21:06:31 CET 2019


Can you show us an example with the data that you are using and the
output from t.test.

A t-value of 1.96 is not an automatic rejection.  It depends on alpha
and the degrees of freedom.  Even if we set alpha at 0.05, 1.96 should
not give a p-value less than 0.05 with finite degrees of freedom.

This also depends on the arguments to t.test.  If the alternative is
set to "Less" then a t value of 1.96 would give a p-value close to
0.975 for high degrees of freedom.

The only time I have seen t.test give a p-value of 1 is when the data
mean exactly equals the null hypothesis mean and the alternative is
the default of two.sided.

For us to diagnose what is going on we need to see your command (how
you are calling t.test) and what data you are using.

On Tue, Mar 12, 2019 at 1:49 PM SMRUTI BULSARI <bsmruti using hotmail.com> wrote:
>
> I am writing this e-mail as I have come across one issue while performing t-test using R. If the function t.test(…) is used, a p-value of 1 is obtained for a calculated t-value greater than 1.96. If the t-value is greater than 1.96, the null hypothesis is rejected. However, if the p-value is greater than 0.05, one may say that there is not enough evidence to reject the null hypothesis. Thus, a t-value of greater than 1.96 and a p-value of 1 leaves the user of R software confused on whether to reject or not to reject the null. Moreover, how can p-value of stochastic process be exactly equal to 1? Can you please guide me on whom should I report this issue to? Or can you please forward this issue to the appropriate person / team?
>
> Thanking you,
>
> Sincerely,
>
> Smruti Bulsari
>
> Assistant Professor
> Department of Human Resource Development
> Veer Narmad South Gujarat University
> Surat - 395 007
> (Gujarat) INDIA
>
> Ph:+91-261-2256071 (Ext. 204)
>
> Alternate E-mail: sbbulsari using vnsgu.ac.in
>
> LinkedIn Profile: https://www.linkedin.com/in/smruti-bulsari-0a30b312/
>
> Blog Posts: https://wordpress.com/posts/smrutibulsari.wordpress.com
>
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.



-- 
Gregory (Greg) L. Snow Ph.D.
538280 using gmail.com



More information about the R-help mailing list