Linked Questions

4
votes
3answers
18k views

How do you show that two populations are statistically similar? [duplicate]

Possible Duplicate: Testing hypothesis of no group differences Suppose I have $k$ samples from 2 independent experiments (service times by 2 methods) and their means are similar. How do I ...
2
votes
0answers
53 views

Method for proving no difference in a set of paired samples [duplicate]

I'm trying to analyze a set of 15 paired samples. The elements of each pair are results of a measurement that produces a scalar value. The first measurement of the pair was done in presence of some ...
0
votes
1answer
15 views

Regarding T-Test for point hypotheses [duplicate]

I have, so far only conducted hypotheses tests having the null hypothesis as a point hypothesis while the research hypothesis is composite. But what procedure shall I follow if my research hypothesis ...
251
votes
150answers
132k views

Famous statistical quotations

What is your favorite statistical quote? This is community wiki, so please one quote per answer.
47
votes
7answers
29k views

When conducting a t-test why would one prefer to assume (or test for) equal variances rather than always use a Welch approximation of the df?

It seems like when the assumption of homogeneity of variance is met that the results from a Welch adjusted t-test and a standard t-test are approximately the same. Why not simply always use the Welch ...
46
votes
6answers
43k views

Percentage of overlapping regions of two normal distributions

I was wondering, given two normal distributions with $\sigma_1,\ \mu_1$ and $\sigma_2, \ \mu_2$ how can I calculate the percentage of overlapping regions of two distributions? I suppose this problem ...
37
votes
8answers
18k views

Is it possible to prove a null hypothesis?

As the question states - Is it possible to prove the null hypothesis? From my (limited) understanding of hypothesis, the answer is no but I can't come up with a rigorous explanation for it. Does the ...
9
votes
3answers
3k views

Equivalence tests for non-normal data?

I have some data that I can't necessarily assume to be drawn from normal distributions, and I would like to conduct tests of equivalence between groups. For normal data, there are techniques like TOST ...
2
votes
3answers
1k views

Test if two samples are equal

I have two samples, say sample A and B, and a negative control. I expect that the sample A to be different than the negative control, so I use a t-test to check for that. Then, I expect sample B ...
1
vote
3answers
4k views

How to find out if two sets of data are equal at 95% Confidence Level in R

I am interested to find a way to identify if two sets of data can be considered statistically different at 95% Confidence level (or any other). To be more specific, my data sets are composed of 5 ...
3
votes
2answers
4k views

How to tell if my variable is a suppressor?

I am analyzing data using path analysis and I am hoping someone here can help. In my model, I am looking at predictors of a variable, $Y$. In the path model, $Y$ has 4 significant predictors lets ...
9
votes
2answers
546 views

Can a narrow confidence interval around a non-significant effect provide evidence for the null?

It is obviously fallacious to assume that failure to reject the null implies that the null is true. But in a case where the null is not rejected and the corresponding confidence interval (CI) is ...
5
votes
2answers
1k views

Equivalence test for two multivariate normal distributions?

I'm trying to compare two samples from multivariate normal distributions to see if their distributions are equivalent (within a factor of epsilon). The standard version of this test is the energy ...
2
votes
1answer
217 views

ANOVA or other test for summed data

I would appreciate any suggestions of how to analyse the following dataset. It was suggested that I use ANOVA, but I wanted to check with the community. I have a protein where I have calculated the ...
1
vote
1answer
189 views

Test for equivalence after sampling into test groups

I want to test the effects of different versions of treatment across multiple test groups of a given population. In order to do that, I want to randomly sample my population into, let's say, 4 groups ...

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