Recent content by noetsi

  1. noetsi

    orthogonalization question

    I have not seen this addressed much in regression (it is central to factor analysis). Doing this would mean that you end up with predictor variables that are unrelated to each other. While that might make analysis simpler it probably would not be very realistic for real world variables...
  2. noetsi

    sas macro

    I was finally able to open the link in post 10 but the appendix which has the macro is not there (I have to pay for it I assume). The only thing that shows up in post 9 is a lot of X's... thanks for posting it.
  3. noetsi

    Statistics in a Pacing Experiment

    You should look at the design of experiment literature particularly in that inside ANOVA to begin with. This addresses many of your questions. I am not enough of an expert to comment with certainty. You should do a power calculation using the effect and uncertainty level you feel comfortable...
  4. noetsi

    sas macro on page 3 for the macro that deals with interval DV (I want the ordinal/binary code).
  5. noetsi

    sas macro

    I don't understand post 4 hlsmith. If you know where the paper for categorical data lives please send it. :) I have one for interval data.
  6. noetsi

    sas macro

    I can do bootstrapping. This is a specific program, of which bootstrapping is part, to run PROC GLIMMIX when the number of groups is too small to generate correct results normally. I don't have the code although I can send the code to deal with interval DV (I really need the code to deal with...
  7. noetsi

    sas macro

    There is a sas macro for bootstrapping when running multilevel analysis with a categorical dependent variable. It is used when the number of second level units is so small that you need to run non-parametric bootstrapping. I have the macro that does this with interval data, but not categorical...
  8. noetsi

    multilevel model likert DV, bootstrapping

    I am doing multilevel modeling. We have only 7 groups which is very small. When you do that non-parametric bootstrapping is recommended. My question is that the examples I have seen have interval data. My dependent variable is a 4 point likert data, ordinal effectively. I don't know a...
  9. noetsi

    Relearning Statistics

    I spent much of my life in graduate programs and learned most of my statistics in books and forums outside of them. :p I think the answer to your question is determined by if you want to do academic or organizational statistics. They vary in that most organizations are not going to do cutting...
  10. noetsi

    Cointegration of two time series

    As I noted in the other thread my understanding is that the correct way of doing time series regression with cointegration is actually vector error correction models - although I suspect relatively few do. I don't think you can use linear regression with non-stationary data period unless they...
  11. noetsi

    Time series regressions

    What type of regression are you running? There are many types of time series regression and each has their own rules. Supposedly vector error correction models are run with cointegration. Or that is the state of the art. Sound like you are doing multivariate arima instead since you are...
  12. noetsi

    Multiple logistic regression interpretation help

    Univariate analysis does not mean anything for multivariate analysis. It is entirely possible the sign can be reversed. It is the impact of x on Y controlling for the other variables (which may be what you mean by confounding).
  13. noetsi

    multilevel model. Dependent variable is not truly interval

    This is the type of comment that drives me crazy. It is in the context of multilevel models. To me it suggest that, ignoring issues of standard errors, you can hardly use OLS for issues that involving variables nested inside others. "Traditionally, researchers tended to use model results at one...
  14. noetsi

    Ensuring correct model specification

    I think, based on satisfaction research I have been involved in, people tend to give highly positive comments even when they are not satisfied as reflected by concurrent qualitative comments made. I don't have a suggestion how to fix that however (I think there is support for this view in the...
  15. noetsi

    How to investigate (multi)collinearity for categorical variables?

    How did you create intentional collinear variables. Multicolinearity is determined by a group of variables not one on one comparisons. VIF is one of the two I know that is recommended. It does not matter if the predictor is categorical or not.