# Linked Questions

2answers
2k views

### Regression on a non-normal dependent variable? [duplicate]

Does it matter if a dependent variable has a normal distribution or not when it is used in a regression?
16answers
102k 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 ...
12answers
5k views

### What are some of the most common misconceptions about linear regression?

I'm curious, for those of you who have extensive experience collaborating with other researchers, what are some of the most common misconceptions about linear regression that you encounter? I think ...
5answers
8k views

### Why do political polls have such large sample sizes?

When I watch the news I've noticed that the Gallup polls for things like presidential elections have [I assume random] sample sizes of well over 1,000. From what I remember from college statistics ...
6answers
5k views

### In layman's terms what is the difference between a model and a distribution?

The answers (definitions) defined on Wikipedia are arguably a bit cryptic to those unfamiliar with higher mathematics/statistics. In mathematical terms, a statistical model is usually thought of as ...
5answers
4k views

### Assumptions of multiple regression: how is normality assumption different from constant variance assumption?

I read that these are the conditions for using the multiple regression model: the residuals of the model are nearly normal, the variability of the residuals is nearly constant the residuals are ...
3answers
42k views

1answer
17k views

### Why are rlm() regression coefficient estimates different than lm() in R?

I am using rlm in the R MASS package to regress a multivariate linear model. It works well for a number of samples but I am getting quasi-null coefficients for a particular model: ...
4answers
9k views

### Which test to choose when the results from t-test and Wilcoxon test are different?

I have a sample of 48. According to the central limit theorem, I may consider means of every continuous variable in my sample to have a normal distribution. However, one variable has a mean of 14 +/- ...
2answers
13k views

### Why do we have to assume normality for a one-sample t-test?

As a consequence of the central limit theorem the sampling distribution of the sample means will always be normal whatever is the distribution of the variable we measure. From our sample we can ...
2answers
7k views

### How does OLS regression relate to generalised linear modelling

Can anyone please shed some light on the relationship between OLS and generalised linear model? Has it to do with the distribution of the error terms, general linear model requires normality in the ...
2answers
4k views

### Non-normality in residuals

I refer to this post which seems to question the importance of the normal distribution of the residuals, arguing that this together with heteroskedasticity could potentially be avoided by using ...
3answers
8k views

### Normality assumption and sample size

I know this is a very debated topic, even on this site, but I still couldn't find an answer to my problem. Recently I am working with large samples (300, 400 and more). For now, I am trying to use ...

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