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  1. 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...
  2. 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...
  3. noetsi

    statistical power for logistic regression

    how do you find out what the power of your test is for logistic regression? I have never run across this in SAS.
  4. noetsi

    predicted probability

    Does anyone know how to generate this in Proc Mixed and Proc Glimmix? When I see this done with an intercept only model I notice the examples are taking the parameter and reversing the sign in generating the following formula to generate predicted probability. pp = e to the parameter value...
  5. noetsi

    Centering predictors

    The only place I have encountered this argument is in multilevel approaches, but obviously it could include logistic and linear regression generally. " As with other forms of regression models, the analysis of multilevel data should incorporate the centering of predictor variables to yield the...
  6. noetsi

    Interpreting logistic regression

    I got findings I have not seen before with this many cases and I wanted a second opinion :) I don't know how to move the attachments around for which I apologize. As you can see in the testing Global Null Hypothesis none of the models are statistically significant. None of the parameters are...
  7. noetsi

    multilevel model. Dependent variable is not truly interval

    I want to run multilevel regression. My dependent variable is a four point likert scale variable (as are predictors in most cases). Can you run multilevel models with a DV that is not classically interval (of course some argue likert scale is effectively interval, but for the moment I am not...
  8. noetsi

    Relationships change, why

    I should say ahead of time I have no theory for this, if I did I would use it. We have a dependent variable that shows whether customers are or are not satisfied. The predictors is how satisfied they are with a variety of other factors like pay, the importance of their work, helping others etc...
  9. noetsi

    Missing values

    I have a satisfaction analysis where the DV is two levels, the predictors are 4 point likert scale data and some people did not fill out all questions. The default for SAS regression is to remove all individuals who do not answer some predictors (you can change this, but that leads to its own...
  10. noetsi

    Logistic regression using Lasso

    Is there any way to do this? There are many ways to use LASSO in SAS but all assume I think a linear model.
  11. noetsi

    Interpreting non-linear ratio

    I am discussing this on another thread, or was, but I realized it would get buried and is another topic. I have a series (31) likert scale predictors for logistic regression (so all variables are measured on the same scale). After a lot of consideration I decided to go with odds ratios to rate...
  12. noetsi

    Logistic regression, minimum sample size

    I have a logistic regression with 394 usable cases. 61 of these are 0, 333 are 1. I have 31 predictors (which can not be reduced or collapsed). I have doubts given various rules of thumb I have seen if the 61 cases are enough to generate accurate results.
  13. noetsi

    correlations with likert data

    I am doing correlation analysis. I have a series of 4 point likert data (high dissatisfied, dissatisfied, satisfied, high satisfied). I want to run correlation analysis. The question is which is better spearman's rho or polychoric correlations. I have thought after looking at the literature it...
  14. noetsi

    ARIMA issue

    After deciding you had no non-stationarity I ran this model suggested by MINIC and SCAN (a ma and ar of 1) proc arima data= tsdata; identify var=spend scan esacf minic; ESTIMATE p=(1) q=(1); run; ods graphics off; when I ran this I got the following warning which I have never encountered in...
  15. noetsi

    Useful links for tests of stationarity

    I found this really useful (given that authors disagree). https://support.sas.com/resources/papers/proceedings15/3294-2015.pdf
  16. noetsi

    Augmented Dickey Fuller

    The ADF has three different tests. The first is random walk, the second random walk with drift, and the third a deterministic trend. For all three tests, If p > alpha non-Stationarity is indicated. The problem I have is that the first test indicates non-Stationarity and the 2nd and third tests...
  17. noetsi

    AIC in ARIMA

    I ran into this in the context of ARIMA. I thought you could always use AIC, whether a model is nested or not - that is the advantage of AIC. "AIC is used to evaluate ARIMA commonly. AIC criteria are only used to compare nested models. This means that the smaller model (e.g., 0, 1, 0)must be a...
  18. noetsi

    sas function that works with date variables

    I know SAS functions that get the difference between two dates. But I can't find a function that works with date variables as compared to values. for instance datdif(('01aug2018'd,'02aug2018'd,"actual") generates fine results but if you do datdif(datevariable1,datevariable2,"actual") I get all...
  19. noetsi

    Odds ratio interpretation

    This comes from SAS odds ratio out put. The second column is the odds ratio SAS prints out (for example .615 for race_p 0 vs 1). One in the DV is being maximized (which means you are employed). The way I interpret this is that if the odds ratio is above 1, then you are more likely to be...
  20. noetsi

    heteroscedastcity

    My residual plots suggest heteroscedastcity to me (fisher should have lost his knighthood for that horrible word). My question is, is it enough to use white's standard errors to deal with this problem. I have about 5 thousand cases if that matters.