bootstrapping

  1. B

    How to continue raw data for Forcasting ~ Holts-Winter

    Hi All, I am new to this forum and i am in need of help regarding the Holt's Winter Method. I've managed to build a forecasting model in excel using the Damped method which works very well. But due to my lack of experience, I am confused on how to continue the raw data as the forecasting...
  2. G

    How is simulation used to check differences of regression techniques.

    I was reading a paper on Bootstrapping with models for count data. (Page 1170) www.researchgate.net/publication/51738951_Bootstrapping_with_Models_for_Count_Data or www.ncbi.nlm.nih.gov/pubmed/22023684 On the paper the author uses the conventional MLE to fit Poisson...
  3. trinker

    Monte Carlo Simulation for Predicting Agile Stories Completed

    A team at work saw this post on using MC for predicting a forcast of stories completed: http://scrumage.com/blog/2015/09/agile-project-forecasting-the-monte-carlo-method/ I have a series of questions as I know of Monte Carlo Simulation but have not used them. 1. Is the basic gist: Get mean and...
  4. H

    Bootstrapping for cox regression analysis

    Hello, I have categorical data (high/low) on a protein which I am investigating its potential role as a prognostic utility. I have run a cox regression with the categorical data and 3 year survival as outcome (dead/alive) I get a significant results (attached). I then ran...
  5. A

    [AMOS] - interpretation of bootstrap indirect effects for one-tailed hypothesis

    Hello all, I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would...
  6. A

    AMOS - interpretation of bootstrap indirect effects for one-tailed hypothesis

    Hello all, I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would...
  7. W

    Bootstrapping pairwise not listwise, a problem with N

    Hi! Hoping someone more statistically minded can help. I have a number of variables with different N (they are performance measures and some have been removed due to not understanding the task). I want to bootstrap the correlations but when I do this in SPSS it excludes listwise rather...
  8. E

    SEM Mediation using bootstrapping approach

    Hi, I am performing mediation analysis using structural equation modelling (I'm using the lavaan package in 'R'). I am using the bootstrapping approach (rather than the causal steps approach) and just wanted to clarify two things; 1) My understanding is that using this approach, the the...
  9. L

    The bootstrap method for medical modelling

    I am part of a team creating a model for paediatric hospitalised patients and would appreciate some help. We are looking to produce an accurate model for weight estimation, using input variables of gender, age and mid-upper arm circumference. This would be helpful as some children arrive in...
  10. C

    Need Bollen-Stine Chi-square

    Hello all, I am typically an AMOS user, but have run into some non-normal data. I am happy that AMOS provides the Bollen-Stine p-value, but I'd love to be able to get the corrected Chi-Square value as well. I think that Mplus can do this (and perhaps R Lavaan). Does anyone now of a way to...
  11. S

    Bootstrapping code help needed in r??

    Hello friends. So I am ready to jump off a building because I cannot figure out this code for my LIFE. Everytime I run it, I get the standard error of 0 (bias=0 too) so obviously I'm doing something wrong because it's using the same sample when I want 1000 iterations. I want the AIC of the...
  12. B

    SPSS 23 Linear Mixed Models -- Why is the Bootstrapping feature grayed out?

    Using SPSS 23 to run linear mixed models. I've set up perfectly good models that run beautifully, but I want bootstrapped estimates and the button for that is grayed out. What is wrong with this program?!?!
  13. M

    bootstrapping correlations Spearman vs. Pearson

    I would like to calculate simple correlations. Since my sample size is quite small and data are not normally distributed I thought about Spearman’s correlations. Then I read about bootstrapping as a distribution free method and, considering my small sample size, I decided to use it with...
  14. P

    Inaccuracy of Non-Parametric Bootstrap for great sample sizes in Excel-VBA

    My aim is to evaluate the performance of parametric and non-parametric Bootstrap under specific circumstances; and particularly their ability to capture the population mean within their produced confidence intervals -from now and on when talking about "coverage" I mean the ability of the...
  15. S

    Help with bootstrapping

    Thanks in advance! I was never taught bootstrapping in my Research Methods of Political Science class, so when I was messing around with SPSS today, I saw it and it intrigued me. I read all about it, but I can't seem to make it work at all. I tried to bootstrap in linear regression and with...
  16. S

    saving predicted probabilities in logistic regression w/ bootstrapping

    SAS allows you to bootstrap a logistic regression and then save the predicted probabilities associated with logistic model. When I try doing that in SPSS, I get the following message: "This command is trying to save new variables while bootstrapping is in effect. The new variables will...
  17. D

    Bootstrapping wald test scores following SUR with panel data

    Hey everyone. Can anyone help me implement these steps into R code? Using this system: [url=http://i.stack.imgur.com/J3qBB.png] I found this piece of R code which might be helpful: # Sample Size N <- 2^12; # Linear Model to Boostrap Model2Boot <- lm( mpg ~ wt...
  18. D

    Bootstrapping test statistics with panel data and SUR

    As a newbie to bootstrapping, I'm having some trouble with developing with critical wald test scores for every observation in my panel dataset. I'm using a Seemingly Unrelated Regression to predict residuals, but then I'm unsure how to resample these and develop these critical wald test values...
  19. D

    Pearsons correlation, confidence intervals, bootstrapping... Statistical nightmare

    I am currently running a project where I have 4 variables and a questionannaire with 4 subscales. I have performed a Pearsons correlation on this (due to high frequency of extreme scores in the questionairre and non-normal distribution of the questionnaire) and have found 2 significant results...
  20. A

    HELP - Bootstrapping

    Dear colleagues, I confirmed that I have included in my SPSS v.20 the add-on "IBM SPSS Bootstrapping" (using the SHOW LICENSE syntax). However, I'm not able to find the "Bootstrapping" button in any dialog box. What do I need to do? Thanks and kind regards