jasp-stats
[Feature Request]: Specify non-zero null hypothesis in t test module
Description
The alternate hypothesis choices for the paired and independent groups situations in the t test module seem to imply a null hypothesis of 0. Some studies may hypothesize that a pre-post difference of at least 5 or more is hypothesized, for example. I see no way to specify this a priori null hypothesis mu
Purpose
To permit the user to specify a non-zero mu (test value) for the null hypothesis in the paired and independent groups t tests, which is readily available in R code.
Use-case
t.test(MyData$After, MyData$Before, mu=5, alternative="greater", paired=T) for the paired t test. A similar specification for mu in the independent groups situation would also be expected.
Is your feature request related to a problem?
No
Describe the solution you would like
Offer the user a choice to add a non-zero null hypothesis value (test value) for the paired and independent groups t test.
Describe alternatives that you have considered
I have looked through the possible specifications in the t test module. I can do the pre-post analysis or test a hypothesized group mean difference using the one-sample t test on the difference scores, but adding a test value option in the paired and independent groups would be helpful. It would not immediately be obvious to most users to approach the analysis using a one-sample test.
Additional context
No response
I believe this would be a simple yet valuable addition, potentially even for the next release, as it can be implemented fairly quickly. @JohnnyDoorn Are you the right person for this (as in maintainer t-test module??
Yes, excellent suggestion! I can do this, or perhaps it could serve as a good intro project for @TarandeepKang (since it's adding a single option, where the one-sample t-test already serves as an example)?
Excellent news! Thank you for working on it!!
All the best,
John
John L. Woodard, Ph.D. Professor of Psychology Licensed Psychologist Editor-in-Chief, Journal of the International Neuropsychological Societyhttps://www.cambridge.org/core/journals/journal-of-the-international-neuropsychological-society Wayne State University 5057 Woodward Avenue, 7th Floor Detroit, MI 48202
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On Mar 27, 2025, at 15:56, Johnny van Doorn @.***> wrote:
[EXTERNAL]
Yes, excellent suggestion! I can do this, or perhaps it could serve as a good intro project for @TarandeepKanghttps://github.com/TarandeepKang (since it's adding a single option, where the one-sample t-test already serves as an example)?
— Reply to this email directly, view it on GitHubhttps://github.com/jasp-stats/jasp-issues/issues/1887#issuecomment-2758371984, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AMYNFK4BCWWJAF3C3JYNPQD2WP7QXAVCNFSM6AAAAABZ5E6GUCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONJYGM3TCOJYGQ. You are receiving this because you were mentioned.Message ID: @.***>
[JohnnyDoorn]JohnnyDoorn left a comment (jasp-stats/jasp-issues#1887)https://github.com/jasp-stats/jasp-issues/issues/1887#issuecomment-2758371984
Yes, excellent suggestion! I can do this, or perhaps it could serve as a good intro project for @TarandeepKanghttps://github.com/TarandeepKang (since it's adding a single option, where the one-sample t-test already serves as an example)?
— Reply to this email directly, view it on GitHubhttps://github.com/jasp-stats/jasp-issues/issues/1887#issuecomment-2758371984, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AMYNFK4BCWWJAF3C3JYNPQD2WP7QXAVCNFSM6AAAAABZ5E6GUCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONJYGM3TCOJYGQ. You are receiving this because you were mentioned.Message ID: @.***>