Programming the statistical procedures from SAS

Paired t-test or wilcoxon signed rank for N=5

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Paired t-test or wilcoxon signed rank for N=5

I have some pre post data for an extremely small sample (n=5). Outcome is continuous and no control. What statistics would be more appropriate to report? Accordingly, is a paired t-test or a wilcoxon signed rank test more appropriate?

I feel 5 data points are insufficient to assess normality. Should i report both?


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‎03-23-2017 11:34 PM
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Re: Paired t-test or wilcoxon signed rank for N=5

Report the Wilcoxon signed rank test result. It is non parametric and the value reported by proc univariate is exact for samples of size < 20.

PG

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Re: Paired t-test or wilcoxon signed rank for N=5

Report mean and maybe direction of change? 5 is too small to make any generalizations - may even want to just report all the numbers. We summarize in first place because too much data to understand otherwise. 5 points don't have that issue. 

Contributor
Posts: 39

Re: Paired t-test or wilcoxon signed rank for N=5

So maybe a t-test and wilcoxon sign test?

Solution
‎03-23-2017 11:34 PM
Respected Advisor
Posts: 4,606

Re: Paired t-test or wilcoxon signed rank for N=5

Report the Wilcoxon signed rank test result. It is non parametric and the value reported by proc univariate is exact for samples of size < 20.

PG
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