# bootstrapping

1. ### Bootstrap confidence intervals for an index calculated on counts

Good morning! I would like to calculate 95% confidence limits for both lower and upper possible values of the Ivlev’s index as it has been done on the below screenshot from a paper of Hebda, Wesołowski & Rowiński (2017) in order to assess the significance of the index values for particular...
2. ### 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...
3. ### 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...
4. ### 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...
5. ### 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...
6. ### [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. ### 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...
8. ### 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...
9. ### 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...
10. ### 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...
11. ### 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...
12. ### 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...
13. ### 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?!?!
14. ### 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...
15. ### 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...
16. ### 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...
17. ### 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...
18. ### 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...
19. ### 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...
20. ### 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...