Recent content by ondansetron

  1. ondansetron

    How to deal with outliers in stock returns? OLS regression January effect

    I would not do anything. Outliers are expected and as long as this value is truly from the population of interest, it is OK; you should not remove outliers because they make things look different than you want. The idea is to accurately represent a phenomenon which may include a lot of typical...
  2. ondansetron

    Moving away from p-values

    Some fundamentals are missing...https://link.springer.com/article/10.1007/s10654-016-0149-3
  3. ondansetron

    Moving away from p-values

    Let's clarify: your post claimed that "...while in Statistics "significant" means probably true (not due to chance)...When statisticians say a result is "highly significant" they mean it is very probably true." None of that is true. Then you also claim you [don't assume Ho is true when...
  4. ondansetron

    Moving away from p-values

    This just isn't true. A very low p-value does not mean very probably true. This is part of the huge misunderstanding by (often) nonstatisticians. A p-value is calculated under the assumption that the null hypothesis is true. P-values do not quantify the probability of "truth" for any "result" or...
  5. ondansetron

    Clinical data sets and R scripts

    A little confusing. Were you given a data set to work on as a homework/class project and an answer key exists somewhere, or are you conducting research? If the latter, your statement is puzzling that you know how to use R but want someone to provide the script because you would create that yourself.
  6. ondansetron

    Long live SAS

    o_O Please feel free to use a quotation to show where I said that (or used foul language...or indicated that I don't have an open mind to those who know much more than I do). Otherwise, let's move along.
  7. ondansetron

    Long live SAS

    Reading comprehension... where is my foul language? Don't forget that your post said, "SAS is for people who completely depend on somebody else for statistical / econometric advice." This is not the same as the slight pivot you tried in reply when you change it to, "...statisticians who used SAS...
  8. ondansetron

    Long live SAS

    Did you get your PhD yesterday? Even people who got the PhDs in stats (that I know) in the early 2000's maybe up to 2015 even usually have a good working knowledge of SAS, just as you get more recent they have more and more R knowledge as well. The statisticians I know who were in school in the...
  9. ondansetron

    Corona hints

    There were some autopsies in China, if I recall, where they saw some fibrosis, but the question is did this exist prior to infection or as a result of huge inflammatory process in the lungs in an intubated ICU patient over weeks. People with underlying lung disease will be more susceptible to a...
  10. ondansetron

    Multivariate regression versus multivariable regression

    If you mean a single outcome (i.e. does the person bleed after surgery (Y/N)) as a function of 2 or more predictor variables, then you want a multivariable regression. If you have multiple outcomes that are being modeled simultaneously then you would want a multivariate regression. The latter...
  11. ondansetron

    Mean of the residuals in Simple Linear Regression *Beginner Alert*

    And mine too, but generally the idea of plotting residuals vs x is to help see if you're misspecified!
  12. ondansetron

    Mean of the residuals in Simple Linear Regression *Beginner Alert*

    Cause that's how the line of best fit is defined (partially), yaknow?
  13. ondansetron

    Mean of the residuals in Simple Linear Regression *Beginner Alert*

    The nonlinearity could imply the mean error is not 0. True model: Y= B0 +B1X + B2X^2 Fit: yhat= b0 + b1x then Y-yhat = residual implies E[(B0 +B1X + B2X^2)-(b0 + b1x)] = E[B2X^2] not equal to zero for B2 and X not zero... so the average error would be B2X^2... this could show as curvature in...
  14. ondansetron

    Book/Website Recommendation

    I will clarify that none of these suggestions are graduate-level. I think with your math background you can handle the probability book given. Mathematics is challenging. Statistics and probability are also hard subjects. Despite what you may see done, there is no quick fix for statistics. I...
  15. ondansetron

    Book/Website Recommendation

    Agreed-- if you meant [calculus, linear algebra, geometry/trig, and some proofwork] as "math background" you definitely need the undergrad probability (and hopefully some mathematical statistics like Hogg and Craig or Wackerly/Mendenhall (at least) to get the most of ISL by Hastie et al. which...