Linked Questions

53
votes
4answers
16k views

How small a quantity should be added to x to avoid taking the log of zero?

I have analysed my data as they are. Now I want to look at my analyses after taking the log of all variables. Many variables contain many zeros. Therefore I add a small quantity to avoid taking the ...
26
votes
5answers
7k views

Is there an explanation for why there are so many natural phenomena that follow normal distribution?

I think this is a fascinating topic and I do not fully understand it. What law of physics makes so that so many natural phenomena have normal distribution? It would seem more intuitive that they would ...
162
votes
76answers
200k views

Statistics Jokes

Well, we've got favourite statistics quotes. What about statistics jokes?
79
votes
9answers
16k views

Regarding p-values, why 1% and 5%? Why not 6% or 10%?

Regarding p-values, I am wondering why $1$% and $5$% seem to be the gold standard for "statistical significance". Why not other values, like $6$% or $10$%? Is ...
35
votes
1answer
8k views

Why do my p-values differ between logistic regression output, chi-squared test, and the confidence interval for the OR?

I have built a logistic regression where the outcome variable is being cured after receiving treatment (Cure vs. No Cure). All ...
8
votes
1answer
9k views

Omitted variable bias in linear regression

I have a philosophical question regarding omitted variable bias. We have the typical regression model (population model) $$ Y= \beta_0 + \beta_1X_1 + ... + \beta_nX_n + \upsilon, $$ where the ...
-1
votes
1answer
49 views

Is there non-distribution (without any distribution rule) data?

My classmate told me: Any data in this world fit a kind of distribution I am just newbie in statistics.I just know normal,...
0
votes
1answer
88 views

how to choose a transformation for left heavy tailed data due to arbitrary upper limit imposed by experimenter?

I have two vectors that look like this: I would like to make a significance test on the paired differences between the two vectors, as well as measure association. The process of data generation is "...
9
votes
2answers
628 views

Famous data visualizations [duplicate]

I am looking for famous, historical, beautiful, impressive, or otherwise noteworthy visualizations based on statistical concepts. I think of examples along the lines of Florence Nightingale's ...
17
votes
4answers
23k views

How to test if my distribution is multimodal?

When I plot a histogram of my data, it has two peaks: Does that mean a potential multi-modal distribution? I ran the dip.test in R (...
37
votes
8answers
18k views

How to test hypothesis of no group differences?

Imagine you have a study with two groups (e.g., males and females) looking at a numeric dependent variable (e.g., intelligence test scores) and you have the hypothesis that there are no group ...
18
votes
1answer
2k views

Central limit theorem and the law of large numbers

I have a very beginner's question regarding the Central Limit Theorem (CLT): I am aware that the CLT states that a mean of i.i.d. random variables is approximately normal distributed (for $n \to \...
65
votes
4answers
25k views

When to use Fisher and Neyman-Pearson framework?

I've been reading a lot lately about the differences between Fisher's method of hypothesis testing and the Neyman-Pearson school of thought. My question is, ignoring philosophical objections for a ...
42
votes
8answers
1k views

Are all models useless? Is any exact model possible — or useful?

This question has been festering in my mind for over a month. The February 2015 issue of Amstat News contains an article by Berkeley Professor Mark van der Laan that scolds people for using inexact ...
27
votes
17answers
5k views

How to describe statistics in one sentence?

When I first started learning statistics, procedures like the t-test, ANOVA, chi-squared and linear regression each appeared to be very different creatures. But now I realise these procedures each do ...

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