fixed effect

  1. A

    Proc Mixed effect interpretation

    Hello, I am analyzing an experiment in which we tested the effect of different treatments on trauma. So, for example, blood pressure (and other parameters) is followed in animals exposed to trauma and treated in different ways. I am using the Proc mixed procedure to analyze my data with...
  2. J

    Split file regression, or Fixed effects Mixed model

    Within a dataset that has a few variables explaining dependent variable A, and influences vary over different categories, it can be obvious to split the file in these categories and run a regression. However, there is also the possibility of running mixed models with fixed factors. What would...
  3. P

    Adjusting for clustered observations

    Hello, I have collected mortality data and several covariates (data on treatment and vital parameters) from patients in two different hospitals. My goal is to analyse effects of treatments on mortality while adjusting for covariates, and using logistic regression would be my first choice to...
  4. M

    nested fixed effects possible?

    Hi, I investigate a problem via a regression model. Firtsly, I have two different ways to measure my outcome, which I incorporate as a two-level factor variable X. However, each of these methods is again influenced by a factor variable with two levels, but these factor variables differ for...
  5. E

    Generalized Linear Mixed Models without mixed effects. A meaningless question?

    Hi there, I know what fixed and random effects in linear models or GLM are. I am using Generalized Linear Mixed Models (GLMM) to handle this. So far, so good. One point worries me, for months actually. In all textbooks, all websites, etc., GLMM is presented as a method to handle...
  6. P

    Mixed models can variable be both fixed and random

    I am conducting an analysis over multiple subjects over several sessions with two types of controls. I want to conduct a mixed model analysis to see if there is a difference with respect to control type. This is what i have so far: I have session nested in subject. Accuracy= dependent variable...
  7. Y

    Importer fixed effect and time fixed effect

    I am running a regression on gravity equation while one of the variable is very significant when importer effect applied but not significant at all when time fixed effect joined. This is very confusing to me because this is the first time i use fixed effect approach. Many Thanks!
  8. R

    [R – lme function] Comparing curves in longitudinal data (growth curves)

    I think my problem is best solved by the use of multi-level models. However, I’d like to confirm if what I’m doing is right, and the use of the function is right too. I work with cells (biology), by doing electrophysiology. I apply to each cell a series of currents, in 20 pA steps, ranging from...
  9. S

    Is the fixed effect model for regression correct

    Hi all, we have a dataset that has final exam Total_score(of students) from 500 random Schools. Some schools have ICT lab other do not have it, indicated by School_Type dummy (1=ICT). We have other variables for school characteristics as well like its size, enrollment, total passed students...
  10. V

    Analysing Panel Poisson Coefficients

    Hi, I'm running a panel poisson regression with fixed effects in Stata. The result in Stata doesn't display a constant. Normally I use standard poisson regression and then the coefficients represent the procentual change of the constant. So I'm confused about how to interpet the coefficients...
  11. B

    Predicted Probability after Logit (...), fe

    Predicted Probability after xtlogit (...), fe Hi! I ran a logistic regression (i.e. my dependent variable y is binary) with fixed-effects. Among a set of covariates z, my variable of central interest, x, is also binary (0/1) and shows a positive significant coefficient. [xtlogit y x...
  12. R

    fixed effect with ancova

    Hi all, I need calculate fixed effect with ancova analysis (spss or genstat). My experiment was on fishes growth with differents diets (8): 15 fishes in each tank (each diet in triplicated, 3 tanks for each diet, total tanks:24). I need calculate p value for fixed effect: tanks and diets...