linear regression

  1. E

    Linear regression

    Hi, I have fit 100000 linear models, M ~ age + age^2, where M is a frequency. I found 5,000 models were significant, but would like to narrow it down to find the most ‘extreme’ cases. Is this possible? Does anyone have any suggestions or any references that may help?
  2. M

    What's the right process to find and use interactions between variables?

    Suppose you want to do a linear regression: y = x1 + ... + x6, and you think there are interactions among the predictors. You can do an exhaustive trial-and-error test for interactions, but that would be multi-testing and thus not a good idea, right? What would be the right procedure to find...
  3. R

    Which statistical method for 2 ordinal IVs and 1 continuous DV?

    I am trying to understand if the weight location in a backpack (high, medium, low) and the grade of the road (0%, 5% and 10%) are related to significant differences in stability, which is my continuous outcome measure. I have 13 participants with full data. Each person has 9 data points See...
  4. J

    Linear Regression Analysis

    Hi, I am trying to do a linear regression analysis on my data for my psychology dissertation. My supervisor has asked my to check whether the assumptions for this type of analysis have been violated, but I have no idea how to do this :confused: Does anyone know how I could go about doing...
  5. R

    goodness of fit - with a twist!

    I have a study with 300 subjects. Each subject has completed a cardio pulmonary test (CPET). Therefore, I have 300 datasets that each contain 1 record every 5 seconds with values for 13 different measures. To simplify things, say I am running a simple linear regression on each of the 300...
  6. H

    Outcome variable in almost 80% of the cases zero. What to do?

    Dear fellow members, I investigate if physical activity is related to learning outcomes in adult students participating in distance learning. Physical activity is measured via online survey research in 1728 students and after half a year their learning outcomes are mapped. Learning outcomes...
  7. D

    R linear model on big table

    Hi all! I have a big table and want to run a linear regression (or other linear model) in R, but not sure how to do that.... this is a very short view of what I have (actually I have got about 5000 sample) Latitude sample48109_1 sample48326_1 sample48827_1 59.8 21 29 129 59.8 18 23 32...
  8. D

    controlling for third variables using partial correlation?

    Hi, all. I would like to know if I can use a partial correlation for my purpose. I want to know if there is a direct association between A and B. Let's say B~A, Then, B is a dependent variable and A is an independent variable. But there might be other factors affecting B and A. Let's say that...