# Recent content by martinl

1. ### Dependent t-test with extra information provided

Oh, I see, now I can clearly see your point. I didn't know that, stats books don't mention that.
2. ### Dependent t-test with extra information provided

Yes, I would conclude there's NO EVIDENCE that there is a difference between before and after measurements. Since 20 is the upper bound of normalcy. So what's the problem?
3. ### Dependent t-test with extra information provided

I was trying to perform a one tailed t-test, with Ho: mu <=20 (given that mu can go up to 20 and still be considered normal). Isn't this correct?

5. ### Dependent t-test with extra information provided

I recalculated it, it is still not significant under Ho: mu <=20. The t-value is negative, but the Critical Value is 1.729 (df=19). So cannot reject Ho. It was 1 tailed.
6. ### Dependent t-test with extra information provided

This image illustrates my calculation. The p value I got from the test is 0.000, and the test is a two tailed test with test value=20. That p value is represented by the far right orange-coloured area. It is a p value from a two tailed test, but I am doing a one tailed test (Ho: mu < 20), so my...
7. ### Dependent t-test with extra information provided

I don't think so, I am doing a one tailed test now, and 0.000 is the probability of getting >20.
8. ### Dependent t-test with extra information provided

Can I calculate like this : The p value from SPSS is <0.001, so half of that will be <0.0005, that's the probability of mean >20. So the probability of mean <=20 is (1 - 0.0005).
9. ### Dependent t-test with extra information provided

Oh, sorry I was wrong. His claim applied to the mean. So you were right. So I did a one tailed test, Ho is "mean difference <20". The SPSS test I used was one sample t test, I set the test value = 20. The resulting p value = 0.000 (see images below). I am wondering: how should I do the rest ...
10. ### Dependent t-test with extra information provided

That would no longer be a paired t-test. What do we do with the paired data? Thank you.
11. ### Dependent t-test with extra information provided

That sounds like a good idea, but his claim applies only to the after measurement, not the mean difference. Would your idea still work?
12. ### Dependent t-test with extra information provided

Dear all, I did a dependent t-test for a medical research, it was comparing before and after measurements. So the dependent t-test should be the right test to use. The after measurements have a wide range. And then the client provided me with another piece of information: "it is very normal...