11k views

### Can I ignore coefficients for non-significant levels of factors in a linear model?

After seeking clarification about linear model coefficients over here I have a follow up question concerning non-signficant (high p value) for coefficients of factor levels. Example: If my linear ...
38 views

### How to do regression model selection if dummy variables are involved? [duplicate]

Original post on stackoverflow: https://stackoverflow.com/questions/28773153/how-to-do-regression-model-selection-if-dummy-variables-are-involved I am trying to do a logistic regression analysis in R ...
8k views

### Univariate non-significant results becoming significant on multivariate analysis---X-ray waiting times

I'm having a look at x-ray waiting times in an emergency department and how these relate to the day of the week and the time of day that requests are ordered. (Want to know if patients have to wait ...
5k views

### What to do with dummy variable that is not significant? [duplicate]

I´m running a binary logistic regression to predict the purchase probability for a product. My model contains mostly dichotomous and categorical variables. One variable, let´s say "decision maker", ...
699 views

### What happens if the full model has the smallest AIC?

Suppose I am modelling a binary outcome $y$ with $n$ covariates. If this model has the lowest AIC among all the other ones...would this be the one to use? Also in dealing with categorical variables, ...
747 views

### Feature Selection with Categorical Variables: Multicollinearity and Statistical Significance

Building a logistic regression model with three categorical features and one continuous. For simplicity, let's say I have the following features and variables: ...
674 views

### Interpreting regression coefficients with a multi-level categorical variable [duplicate]

How do I interpret the coefficients of a Regression with 1 continuous + 1 categorical predictor (with 4 levels - e.g., months) Specifically, is the 1st coefficient equal to that of the 1st month or ...
409 views

### How to drop certain values for a factor variable while fitting a GLM? [duplicate]

My response var is a binary variable. In the predictor variable i have a type variable with levels as l1,l2,l3,l4. And when i run a logit (glm(redonse ~ type, family = "binomial"), Some levels of type ...