Linked Questions

71 votes
7 answers
90k views

What is a "saturated" model?

What is meant when we say we have a saturated model?
user avatar
110 votes
3 answers
114k views

Does an unbalanced sample matter when doing logistic regression?

Okay, so I think I have a decent enough sample, taking into account the 20:1 rule of thumb: a fairly large sample (N=374) for a total of 7 candidate predictor variables. My problem is the following: ...
user avatar
  • 1,203
61 votes
1 answer
19k views

Logistic regression in R resulted in perfect separation (Hauck-Donner phenomenon). Now what? [duplicate]

I'm trying to predict a binary outcome using 50 continuous explanatory variables (the range of most of the variables is $-\infty$ to $\infty$). My data set has almost 24,000 rows. When I run ...
user avatar
  • 743
7 votes
3 answers
9k views

Can I fit logistic regression over a dataset with only categorical data?

I have a dataset which contains only categorical data i.e.A,B,C,D (like factors) for each predictor. There are 10 predictors and the dependent variable is binary, <...
user avatar
  • 1,593
6 votes
2 answers
3k views

Rare Events Logistic Regression

Suppose the event of interest occurs in approximately $10 \%$ of the cases where the number of cases is around $5,000$. Should you use a penalized logistic regression for this or is regular logistic ...
user avatar
2 votes
2 answers
4k views

R - Model selection in Glmer

Having troubles to perform a model selection for glmer in R. I'm using the package lme4 with the following structure: ...
user avatar
3 votes
1 answer
442 views

Logistic regression with small number of cases

The project I'm working on attempts to explain why an NGO is present (1=present,0=not present) in some countries (15) but not others. As I'm working with country-level data, my sample size is ...
user avatar
4 votes
2 answers
74 views

Is there a way to increase the number of predictor in a logistic regression when sample size is small?

One of the dependent variables in my dataset is a binomial variable indicating whether an invasive species has been eradicated (with $n_{1}$ = 23) or not (with $n_{0}$ = 75) after the use of a certain ...
user avatar
  • 383
2 votes
1 answer
415 views

Feature selection and PCA in logistic regression with rare events data

I am working on a census-related project where I am interested in assigning to everyone a score that estimates the probability they will have a demographic characteristic of interest. In this case, ...
user avatar
  • 2,640
0 votes
2 answers
228 views

Binary logistic interpretation (spss)

I'm trying to conduct a binary logistic regression to see how each feature of male crabs contributes to being selected by females. the dependent variable is being selected or not selected which is ...
user avatar
1 vote
0 answers
84 views

Logistic regression with rare events [duplicate]

Could somebody provide some references on the application of logistic regression for modelling rare events? So far I've come across three methods with the main references below: Exact logistic ...
user avatar
0 votes
1 answer
78 views

Independent variables minimum counts for logistic regression

I have about 100 samples collected to know the knowledge status of people and it's distributes almost 50 50. The problem is some of my indipendent variables while making 2x2 the cell value is very ...
user avatar