Linked Questions

4 votes
3 answers
21k 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 ...
Jacob's user avatar
  • 235
2 votes
0 answers
63 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 ...
n-hedus's user avatar
  • 21
0 votes
1 answer
27 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 ...
Ishan Kashyap Hazarika's user avatar
0 votes
0 answers
22 views

Test if difference between two groups across 4 categories [duplicate]

I want to make a sensitivity analysis to test whether there is a statistically significant difference between the observations included for the study (n = 100,000) and the excluded observations (n = ...
user12541161's user avatar
282 votes
153 answers
147k views

Famous statistical quotations

What is your favorite statistical quote? This is community wiki, so please one quote per answer.
53 votes
8 answers
37k 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 ...
russellpierce's user avatar
50 votes
6 answers
54k 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 ...
Ali Salehi's user avatar
39 votes
8 answers
24k 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 ...
Pulkit Sinha's user avatar
10 votes
3 answers
5k 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 ...
Ryan C. Thompson's user avatar
2 votes
3 answers
2k 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 ...
Maciej Trybiło's user avatar
3 votes
2 answers
6k 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 ...
SLL's user avatar
  • 31
1 vote
3 answers
6k 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 ...
user3329055's user avatar
10 votes
2 answers
736 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 ...
ATJ's user avatar
  • 1,851
4 votes
2 answers
808 views

How to test if two means are significantly similar?

I'm trying to run an experiment to see if my test and control (in this case 2 survey types) are similar, as opposed to significantly different, from each other. Is there a test/way to do this? almost ...
jc315's user avatar
  • 71
5 votes
2 answers
2k 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 ...
user1871183's user avatar

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