Linked Questions

3
votes
0answers
60 views

If you know a factor is significant, what is a reason why R might think it's not? [duplicate]

I'm running a logistic regression model where anecdotally I expected age to be a very large factor. If you see from the charts I made in Excel before running the model through R, this is how the ...
118
votes
19answers
28k views

Most interesting statistical paradoxes

Because I find them fascinating, I'd like to hear what folks in this community find as the most interesting statistical paradox and why.
37
votes
5answers
15k views

How to resolve Simpson's paradox?

Simpson's paradox is a classic puzzle discussed in introductory statistics courses worldwide. However, my course was content to simply note that a problem existed and did not provide a solution. I ...
12
votes
2answers
25k views

Positive correlation and negative regressor coefficient sign

Is it possible to obtain a positive correlation between a regressor and a response (+0,43) and, after that, obtain a negative coefficient in the fitted regression ...
11
votes
2answers
15k views

Exponentiated logistic regression coefficient different than odds ratio

As I understand it, the exponentiated beta value from a logistic regression is the odds ratio of that variable for the dependent variable of interest. However, the value does not match the manually ...
11
votes
5answers
12k views

Clustering as a means of splitting up data for logistic regression

I'm trying to predict the success or failure of students based on some features with a logistic regression model. To improve the performance of the model, I've already thought about splitting up the ...
2
votes
2answers
2k views

Positive correlations to dependent variable, but negative coefficients

First of all, sorry for the huge pictures, but I'm in desperate need of some input and help on the results following a study. I'm trying to interpret the results from my study, but I can't quite ...
2
votes
1answer
2k views

T test on achievement data before and after an event

Please note Edit Below: I have to establish the statistical relevance of a hypothesis which is of the form H0 = The event lead to an increase in performance Ha = The event caused a negative or no ...
4
votes
1answer
1k views

Correlations with a linear combination means correlation with individual variables?

I was having this conversation with someone, and I feel like I have an explanation, but would greatly appreciate if someone could verify whether what I'm thinking is just completely wrong. He made ...
1
vote
2answers
429 views

Better method to estimate gender gap: difference between medians or median gap by occupation?

I'm doing some analysis of Bureau of Labor Statistics data on wages earned by men and women, and I'm trying to determine which of the two methods I've used is the better estimate of the gender wage ...
2
votes
1answer
426 views

A question about resolving Simpson's paradox by normalization

I recently asked a question about Simpson's paradox. Suppose we are concerned about making some choice about an arbitrary element of a population. Recall that Simpson's paradox arises when the answer ...
4
votes
1answer
149 views

What can I validly conclude about a variable that becomes significant and switches sign when other variables are included in the model?

I have a dataset dat where each row represents a soil sample, with independent variables chemical measurements a, ...
0
votes
0answers
481 views

When to collapse data on subject level?

I have a question about when to collapse raw data to means per unit (e.g., subjects). In my data I have the following variables: id: subject id ...
2
votes
1answer
134 views
0
votes
0answers
28 views

Relationship between correlation and multiple hierarchial regression

I got a negative correlation value between two variables. Results of running Multiple hierarchical linear regression on the same variables indicated a positive beta coefficient between them. Explain ...