14k views

### How to test for simultaneous equality of choosen coefficients in logit or probit model?

How to test for simultaneous equality of choosen coefficients in logit or probit model ? What is the standard approach and what is the state of art approach ?
38k views

### How to test the statistical significance for categorical variable in linear regression?

If in a linear regression I have categorical variable... how do I know the stastical signifance of the categorical variable? Let's say the factor $X_1$ has 10 levels... there will be 10 different ...
21k views

### Wald test in regression (OLS and GLMs): t- vs. z-distribution

I understand that the Wald test for regression coefficients is based on the following property that holds asymptotically (e.g. Wasserman (2006): All of Statistics, pages 153, 214-215):  \frac{(\hat{...
19k views

### centering and scaling dummy variables

I have a data set that contains both categorical variables and continuous variables. I was advised to transform the categorical variables as binary variables for each level (ie, A_level1:{0,1}, ...
7k views

### If and how to use one-tailed testing in multiple regression

I have one-sided hypotheses that I want to test with multiple regressions. Does anyone know how to perform a one-sided hypothesis testing? I heard of different positions regarding this matter ("not ...
7k views

### Different p-values for anova() and summary() in glm.nb

using this code ...
1k views

### What do p-values for levels of a categorical variable represent in Poisson regression?

I have a Poisson model with varying densities: set.seed(1) df = data.frame(density = 1:5, events = rpois(2000, 1:5)) If I regress on this, I get that the ...
2k views

### How can I isolate the effects of a particular independent variable?

I am planning a study and am not sure which statistical test I should use. In this study, I have multiple independent variables. Some of these variables are categorical, while others are numerical. I ...
2k views

### Control variable in regression

I need to run multiple regression with 2 IVs and 1 DV and include a control variables. The control variable is "Type of House" and has 4 categories: 1=bungalow, 2=apartment, 3=penthouse and 4=...
604 views

### Fitting a Logistic Regression Without an Intercept

Based on the answer here: Significance of categorical predictor in logistic regression I tried adding a "-1" to my model to fit it without an intercept, and see the correlations directly. It looks ...
569 views

### Which intercept R selects (binomial glm)?

I have a problem with an analysis. I'm doing a binomial glm with two categorical factors that are loc and trat. I do not understand how R deals with the intercept (what statistical explanation does ...
548 views

### Logistic regression: Overall significance of categorical predictor in SPSS

In SPSS, when performing binary logistic regression using multiple categorical predictors, a significance level is detailed for the variable overall in addition to each category. This strikes me as ...
487 views

### Does ANOVA work with percentages, like Conversion Rate?

I'm trying to figure out if I can perform ANOVA on conversion rate. Would this work? Editing for more information: The question we are trying to solve is for our AB Testing program. Oftentimes we ...