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### What are common statistical sins?

I'm a grad student in psychology, and as I pursue more and more independent studies in statistics, I am increasingly amazed by the inadequacy of my formal training. Both personal and second hand ...
88k views

### Statistics interview questions

I am looking for some statistics (and probability, I guess) interview questions, from the most basic through the more advanced. Answers are not necessary (although links to specific questions on this ...
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### Is this really perfect separation in logistic regression, or is something else going on?

I have some data on patients presenting to emergency departments after sustaining self-inflicted gunshot injuries, stored in a data frame ("SIGSW," which is ~16,000 observations of 47 variables) in R. ...
8k views

### Variable is significant through stepwise regression but not in final model's summary; which should I report?

I used generalized linear mixed models (with the glmmADMB package) to identify environmental factors related to parasite abundance in rodents. I used stepwise ...
6k views

### Forward or backward sequential feature selection?

I was trying to carry out feature selection on a dataset using sequential feature selection. The dataset contains more than 5000 observations (rows) and 22 features (columns). Now I see that there are ...
26k views

### How to use R anova() results to select best model?

Newbie question using R's mtcars dataset with anova() function. My question is how to use anova() to select the best (nested) model. Here's some example data: ...
4k views

### Should I use ANCOVA or multiple regression with dummy variables?

I am writing a manuscript using an experimental design which predicts interactions between 1 continuous variable and multiple dichotomous variables, all predicting a continuous variable. As is ...
373 views

### What variables need to be controlled for in regression?

There are numerous discussions on this site concerning how to control for certain variables in regression analysis. How exactly does one “control for other variables”? How do you "control" ...
702 views

### Significant differences among fit lines - ANCOVA not enough?

I often am in the situation of having data sets consisting of an independent variable, a dependent variable, and a factor with multiple levels - for instance, calibration curves for an instrument ...
1k views

### Stepwise model selection using Generalized Akaike Information Criterion

I run a series of models using gamlss stepGAIC() model selection. The problem that I have is that in gamlss, ...
1k views

### Alternatives to stepwise discriminant analysis for feature selection on hyperspectral data

I am new to R and to hyperspectral data analysis. However, in my research, I have found that many warn against using Stepwise discriminant analysis (using Wilk's Lambda or Mahalanobis distance) for ...
2k views

### Repeated measures - random effects for logistic regression in R?

Study design 504 individuals were all sampled 2 times. Once before and once after a celebration. The goal is to investigate if this event (Celebration) as well as working with animals (sheepdog) ...
2k views

### R Linear model step NA values

My aim is to carry out a generalized linear model (glm) with 1 response variable and 13 explanatory variables.Unfortunately 3 out of the 10 explanatory variables contain NA values (2/3 of data set of ...