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  1. ondansetron

    After performing an ANOVA, if it fails to reject H0 how we re-arrange the model?

    The goal of an analysis isn’t to “make it significant,” I agree with @Buckeye that you should report it as is. If the omnibus test isn’t significant then that’s what you’re left with.
  2. ondansetron

    Multiple Regression

    Sorry, it wasn't clear to me: which single variable are you trying to predict? Also, yes, sorry I wasn't clear-- as @GretaGarbo said, the signs of coefficients within a model (pos/neg) do not restrict you from using the model. As far as graphing a multiple regression, you can absolutely do...
  3. ondansetron

    How to argument for non-significant results

    In general, post-hoc power/sample size calculations are only valuable for helping plan a future study. In the current study, it adds no new information as the post-hoc power calculation is just a transformation of the p-value. You are also correct that you can't use p-values or CIs to argue...
  4. ondansetron

    Multiple Regression

    Which is the outcome/dependent variable (what are you trying to predict)? How is it measured? What variables do you think help explain/predict/influence that outcome variable? How are they each measured? What is your sample size? Multiple regression may be a reasonable option, but knowing...
  5. ondansetron

    Standard deviation 0

    how many people were in the group? I just meant you could cay all participants rated Item A as 5/7.
  6. ondansetron

    Standard deviation 0

    So you are saying you have some variable you wish to analyze for a specific question, but every single recorded value is the same? Was this by design or were participants able to choose something different (what was the range of choices?)? Without variability the best you could do would be to...
  7. ondansetron

    Help identi

    I wonder if this somewhat mimics a multimodal pattern based on the traffic each day of the week and variation in the incubation period before symptoms present with a decreasing intensity as the source is identified and cleaned? Lots of specific claims but just a thought...
  8. ondansetron

    read.csv adds weird character to my first column header

    That makes sense. Thanks. I'm not very versed in coding. Anything I've done in SAS I just keep a log of my code and the output it generates and store that in a Word file for reference if needed. Probably not the best. I'll try to think about that in the future.
  9. ondansetron

    read.csv adds weird character to my first column header

    Thank you! 1) Why don't you like the "file.choose()" option? 2) What do you mean "file is UTF-8 encoding and against recommendation whatever..." what does the emboldened text mean? Is it against recommendation to us UTF-8?
  10. ondansetron

    read.csv adds weird character to my first column header

    New one-off question: I am trying to learn importing data with R. I am following Mike Marin's Youtube lectures. I saved his excel sheet as .csv and tried the read.csv command, and everything seems to go well. I am totally new to R, essentially. When I try to view the data, the console shows a...
  11. ondansetron

    Multinomial Logistic Regression - when to exclude predictor

    My mistake, I accidentally left off "un-" in "unordered" DV. I corrected my post. If X3 goes against theory, there isn't strong evidence it's a predictor, but I would otherwise leave X3 in the model. I see the connection that you were making with my other comment on a dummy variable. Since the...
  12. ondansetron

    Dose Response Curve (log logistic regression)

    I would look at Agresti's Categorical Data Analysis 3rd edition (978-0470463635). Chapter 8 discussed cumulative logit proportional odds (example 8.2.4 "Happiness") and continuation-ratio logit (example 8.3.7 "developmental toxicity") and these may be useful for you to look at depending on the...
  13. ondansetron

    Multinomial Logistic Regression - when to exclude predictor

    My example before, if I recall, was for an independent variable with 3 levels and k-1= 2 dummy variables (and not removing a dummy because one was non-significant on an individual test). In any case, let's clarify: you're saying Y (a,b, or c) is an unordered variate that you suspect is a...
  14. ondansetron

    Book Review - Essentials of Bio statistics: An overview with the help of software

    Since there is no way for us to actually view any of the book, this seems more like an advertisement?
  15. ondansetron

    Finding E((x-a)^2)

    Is a symbolic of a constant (the same number) subtracted from each X value or is a another RV?
  16. ondansetron

    Understanding the significance of my logistic regression model

    I agree with mostly everything posted in reply. @hlsmith is right to point out that multivariable and multivariate are very different things though they sound the same and the terms are used incorrectly quite frequently in medicine (multivariable is the case of a single outcome modeled by some...
  17. ondansetron

    Fleeting/Random Thoughts

    I asked because it's interesting to me to see some programs say they want XYZ and I feel as thought that the bare minimum to pass through the program (maybe with a bit of self study for those students) but to really be successful and get the most from it, it would imagine almost a full bs or MS...
  18. ondansetron

    F test not significant but coefficients are

    On this topic, it is also possible to a priori plan comparisons without using the F-test, but if you're using the F-test it doesn't make as much sense to do comparisons if the F-test is nonsignificant.
  19. ondansetron

    Fleeting/Random Thoughts

    I suppose I'll try to help it go for 2 days: What are the prerequisite math courses for an MS/MA in Statistics? A Ph.D.? I know many programs says the minimum is calculus through multiple integration, linear algebra, and often real analysis for the PhD is mentioned. What are the...
  20. ondansetron

    F test not significant but coefficients are

    I think remembering the purpose of each test and that they aren't asking the same question (barring special case) is helpful to avoid confusion over this situation. There are minor bits of mathematics that can show why this might occur, but it's arising from a process that isn't necessarily...