Linked Questions

1
vote
1answer
421 views

Fitting data to a log-normal distribution [duplicate]

For a simulation study I've been trying to find an appropriate distribution for job handling times in R. I have a very large dataset of 77010 records (handling time in seconds). I've been exploring ...
245
votes
148answers
129k views

Famous statistical quotations

What is your favorite statistical quote? This is community wiki, so please one quote per answer.
294
votes
16answers
97k views

Is normality testing 'essentially useless'?

A former colleague once argued to me as follows: We usually apply normality tests to the results of processes that, under the null, generate random variables that are only asymptotically or ...
56
votes
13answers
15k views

If we fail to reject the null hypothesis in a large study, isn't it evidence for the null?

A basic limitation of null hypothesis significance testing is that it does not allow a researcher to gather evidence in favor of the null (Source) I see this claim repeated in multiple places, but I ...
13
votes
1answer
22k views

Should I use t-test on highly skewed data ? Scientific proof, please?

I have samples from a highly skewed (looking like an exponential distribution) dataset about users' participation (e.g.: number of posts), that have different sizes (but not less than 200) and I want ...
6
votes
4answers
7k views

Should I use t-test on highly skewed and discrete data?

I have samples from a highly skewed dataset about users' participation (e.g.: number of posts), that have different sizes (but not less than 200) and I want to compare their mean. For that, I'm using ...
2
votes
2answers
5k views

Tests for lognormal distribution

I have some data in the following manner. 10 3 4 5 6 9 ... I have to check that the difference between returns is log normal by doing ln(return/previous return). I know some tests for normality if i ...
1
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2answers
2k views

Estimating “Probability” in normal probability plot

I plotted normal probability plot in R using qqnorm and qqline. I want some help on: How to estimate "probability" that a data ...
1
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2answers
2k views

Uniform distribution testing

I'm trying to determine the best way to check if a sample of angles is uniformally distributed. As such I've built two toy functions to see what type of sampling error to expect from actually uniform ...
11
votes
1answer
297 views

Hypothesis Testing and the Scientific Method

Reading the answers to this thread, I started wondering about how Hypothesis Testing relates to the Scientific Method. While I have a good understanding of both, I am having a hard time drawing the ...
1
vote
0answers
217 views

Is there any way to assess goodness of fit using equivalence tests sense?

To assess goodness of fit, chi-squired test and Kolmogorov-Smirnov test, etc. are traditionally recommended. However considering necessity of equivalence tests, these tests seems not to be suitable ...
0
votes
0answers
79 views

Testing for normality - low p-value

I've a dataset with about 12k values given. It looks like this: When I try to test for normality I get following results, where p-value is extremely slow: ...
1
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0answers
41 views

How to test hypotheses properly? [duplicate]

I have a homepage which I would like to change in some ways. I would like to place a commercial banner on it Ha. In this regard, I dont want the change to affect ...