bootstrapping

  1. L

    Mediation, Bootstrapping and Sample Size

    I'm new to statistics overall, and even newer to mediation but I'm attempting to analyze data using Process for SPSS. Before anything else, do I need a specific minimum sample size and how do I determine this? Does bootstrapping take care of this, and then, how many bootstrapping samples do I...
  2. A

    confidence interval via bootstrapping

    Hello everyone, I'm new to Stata and trying to write code to find a confidence interval via bootstrapping for an odds ratio. For the odds in the numerator, the probability of event is calculated from averaging predicted probabilities after model coefficients are estimated using only...
  3. F

    bootstrapping and predictive logistic model

    Hello members. I don't have experience with programming in Stata, then, please, I need help with this: I am developing a predictive logistic model. The regression coefficients were selected using the stepwise method: . xi: sw, lr pe(.05 ) pr(.051) lockterm1: logistic depvar (var1...
  4. victorxstc

    Bootstrapped binary logistic regression in R

    I am trying to run a bootstrapped binary logistic regression. I have loaded the dataset manually into Rstudio (don't know the syntax yet! actually the syntax I learned from Rcommander didn't work in Rstudio); and here is my code for the bootstrapped regression (thanks to this site): (the...
  5. U

    proper sample size and number of estimation for comparing two predictors' AUCs

    Hello, I am trying to do classification of patients by using different predictors. I want to do bootstrapping for a number of times so that I can come up with a set of Area Under Curve's (AUCs) of ROC curve for each predictor and then compare their effectiveness in classification by...
  6. H

    Meaning of bootstrapping residuals

    What does it physically mean when I bootstrap residuals in a regression problem. Like when I bootstrap residuals and create synthetic data does it mean I am hypothetically doing some experiments(virtual experiments which are represented by synthetic data). Or does it mean I am just randomly...
  7. E

    Why use Kruskal-Wallis?

    Hi, I am putting together a course on inference techniques to use when the predictor variable(s) are categorical (ie. have no meaningful order). I am wondering if the Kruskal-Wallis test is still relevant given modern software. My understanding of K-W is that it is a nonparametric...
  8. D

    mediation analysis

    hello there, I can't figure out if I still need to report the Baron and Kenny steps in a mediation analysis, if I'm carrying out a bootstrap anyway. Can someone tell me what the B&K steps would tell me over and above the bootstrap please, and whether they still need to be reported? Thank you! :)
  9. S

    Constrained Bootstrapping

    I need to generate bootstrapped data sets from matrix with the following constraints: 1. The row sums remain constant, i.e., the same as the original matrix 2. Autocorrelations for each matrix row in the original matrix is preserved How do I go about this? My understanding is that there are...
  10. SiBorg

    Bootstrapping - Should/Can I add the bias to the sample median?

    Dear All I'm trying to analyse a questionnaire with responses to questions ordered on a Likert Scale ( 1= Disagree strongly to 5 = Agree strongly). We are comparing question responses between two groups of students, one group (n-25) who saw a video, one group (n=35) who were given a...
  11. CB

    Bootstrap bca confidence intervals for large number of statistics (boot)

    (This isn't really a question thread - I'm just providing some possibly useful code, and asking for suggestions on how it can be improved). The boot.ci function in the boot package allows users to get confidence intervals for particular statistics, with the limits obtained via bootstrapping...
  12. G

    Help to interpret bootstrap and sobel results from spss

    Hi, I'm trying to understand the meaning of these results - my hypothesis is that EA mediates between CNFU and PI. Is the mediation full or partial? What does the insignificance of CNFU mean? What else can I learn from these results? VARIABLES IN SIMPLE MEDIATION MODEL Y...
  13. O

    Bootstrapping question - comparing classifier accuracy

    Hi, I'm developing a classification system for objects. I have a total of 20 different objects that the system should classify, but I want to test the system with a varying number of classes. (3 objects at a time, 4 objects at a time etc.) What I thought of doing is the following: For each...