Search results

  1. ondansetron

    How to correctly interpret log-rank test results

    Also need to consider whether the curves cross because the survival functions are different and non-proportional OR the survival/hazard functions are actually the same and the proportional hazards assumption is not an issue (since the hazard functions are identical, i.e. the observed crossing is...
  2. ondansetron

    Linear Mixed Models

    Beta regression may also be an appropriate option.
  3. ondansetron

    Fleeting/Random Thoughts

    Windows defender is now a strong, competitor in the free antivirus market. Only problem is it is incredibly protective and often blocks things it shouldn’t. I’ve had it 2 weeks now and am constantly adding exceptions to the program list.
  4. ondansetron

    Comparing multiple means to a hypotetical value

    Unfortunately, making assumptions to simplify analysis or making assumptions cause bozos in the field do it does not make it right or even reasonable. Medical researchers often insist on chopping up continuous variables into categorical ones but almost no relationships in biological systems...
  5. ondansetron

    Likert item analysis: ANOVA and Kruskal-Wallis assumptions violated

    I think if you could add more specific details to each this would be helpful: 1) Are you trying to show equivalence (which a standard hypothesis test cannot do) or are you trying to show evidence of a difference? What is the outcome of interest (a score or multiple scores on a survey)? How would...
  6. ondansetron

    Comparing multiple means to a hypotetical value

    Why do you say that mortality rates (bounded on 0-1 or 0-100%) should ideally be normally distributed?
  7. ondansetron

    Likert item analysis: ANOVA and Kruskal-Wallis assumptions violated

    A couple points of clarification before shooting off possibly ill-informed advice. 1) What are you specifically trying to answer/know? 2) have you collected other variables? If so, how are they measured and what are they? 3) Why does your advisor insist on ANOVA?
  8. ondansetron

    Comparing unique items on a Likert scale

    I think we'll just have to write it off as miscommunication because I don't see a sarcastic comment. Text isn't a good medium to convey attitude and intentions.
  9. ondansetron

    Comparing unique items on a Likert scale

    :eek: Don't be too sensitive. You're asking for help, @GretaGarbo wasn't inappropriate to note the distinction.
  10. ondansetron

    random experimental data with prespecified odds ratio and CI

    If you want a multivariate regression, you need more outcomes since multivariate refers to at least 2 outcomes analyzed simultaneously. Perhaps you meant multivariable which refers to at least 2 predictors...?
  11. ondansetron

    Logistic regression curve looks like linear regression

    Can you show us the plots? What is being plotted on the Y axis in each case? for the logistic regression, the log odds should be roughly linear as a function of the x-variables, but if you're plotting the predicted probabilities, this would be sigmoidal (or a smoothed function of the observed 0...
  12. ondansetron

    Backing out into a p-value for clinical trial

    Need to clarify the terminology since this may frame the answer. You have the population (all possible participants) or a sample (some "subset" of a much larger possible total, generally)?
  13. ondansetron

    pre-publication testing of one-click auto-analysis tool

    I think it is more challenging to misuse R or SAS syntax since it tends to be more deliberate and require a bit more thought than spss, for example. I agree that we shouldn’t get rid of the tools because of bad operators. I take the same stance on the silly “ban the pvalue” arguments; why...
  14. ondansetron

    pre-publication testing of one-click auto-analysis tool

    I think items like this are more likely to contribute in a negative manner given the way people already egregiously misuse point and click softwares that require little thought prior to use and facilitate p hacking. An automated process removes the little cognitive effort that people needed to...
  15. ondansetron

    Logistic regression for prediction of outcome?

    From a standard logistic regression you won’t be able to conclude that “earlier removal makes no difference”.
  16. ondansetron

    Rolling 4 dice, probability of a sum=S

    Working on a problem (not homework for me) regarding the probability of a particular sum achieved by rolling n fair 6-sided dice. The specific problem required me to find the probability that four dice are rolled and the sum is 21. I said 6^4 possibilities = denominator. The only possible...
  17. ondansetron

    Difference between multiple regression and multivariable linear regression?

    They were wrong unless you had multiple Y variables (outcomes) analyzed simultaneously. As you later said, PCA is a type of multivariate analysis.
  18. ondansetron

    Difference between multiple regression and multivariable linear regression?

    Not to complicate it further, but essentially multiple regression can be thought of as the same as multivariable but these are different from multivariate as @hlsmith pointed out. The latter is multiple outcomes simultaneously where the former is multiple independent variables. (But you could...
  19. ondansetron

    Anyone can help me with choosing classes?

    I would look into mathematical statistics coursework and a real analysis course which will help you more readily build on your stat knowledge because graduate stats programs will likely be more beneficial if you have prior work in math stat, probability and calc, linear algebra, and real analysis.
  20. ondansetron

    R programming

    I see that makes more sense, I think, than what they gave me. Thanks!