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Calculating t-test p-value for groups containing only 2 samples

Is there any meaning to calculate the p-value for groups of only 2 samples? I mean......I suppose that we can but is it right to do that with so few samples?

t-test p-value
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updated by Devon Ryan Devon Ryan • written by yuyu • yuyu

1 answer

This is more appropriate for Cross Validated. Having said that, no, there isn't much point to running a T-test with only two samples per-group. You'll get a p-value, but you'd be well advised to not read much into it unless you happen to know something a priori about the within-group variance.

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written by Devon Ryan Devon Ryan

Then how about calculating the p-value between two samples in qPCR, each having 2 replicates?

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written by yuyu • yuyu

I assume that the "replicates" are the normal qPCR technical replicates. Again, you can get a p-value, but it's hard to read much into that. A small number of samples will always result in high degrees of uncertainty.

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written by Devon Ryan Devon Ryan

Yes my replicates are technical replicates. I agree with your opinion but the lab where I currently belong to wanted me to calculate this p-value and see if the difference between two samples are significant........I told them that the value will not mean much but they even said that many other publications do the same thing.... Anyway, thank you very much for the answer!

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written by yuyu • yuyu

I'm sure they'd jump off a bridge if others were doing that too.

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written by Devon Ryan Devon Ryan

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