## Original Sample(O), Sample Mean(M), Standard Deviation(STDEV)

Small talk on SmartPLS that does not correspond to the other forums!
KIHO KWON
PLS Junior User
Posts: 9
Joined: Tue May 15, 2018 1:37 am
Real name and title: Mr. KIHO KWON

### Original Sample(O), Sample Mean(M), Standard Deviation(STDEV)

Hi.

When I use standard bootstrapping, 'Original Sample(O)', 'Sample Mean(M)' and 'Standard Deviation(STDEV)' are given.

What does 'Original Sample' mean by?

I think 'Sample mean' is the results from all resamples in the bootstrap procedure and 'STDEV' is the results from all resamples in the bootstrap procedure as well. Is it right?

Because I have some errors below, I have to calculate t statistics and p value manually. But I am confused a little bit.

Thanks
KIHO KWON
Attachments
regular bootstrapping result.PNG (28.43 KiB) Viewed 627 times

jmbecker
SmartPLS Developer
Posts: 932
Joined: Tue Mar 28, 2006 11:09 am
Real name and title: Dr. Jan-Michael Becker

### Re: Original Sample(O), Sample Mean(M), Standard Deviation(STDEV)

Original Sample is the value of the parameter in the original sample.

And yes you are right:
Sample Mean is the mean of the estimated parameter over all subsamples. It is only important for bias corrected confidence intervals to calculate the bias.
STDEV is the standard deviation of the estimated parameter over all subsamples. In bootstrapping it equals the standard error and is thus used to calculate the t-statistic (Original/STDEV).
Dr. Jan-Michael Becker, University of Cologne, SmartPLS Developer
Researchgate: https://www.researchgate.net/profile/Ja ... v=hdr_xprf

KIHO KWON
PLS Junior User
Posts: 9
Joined: Tue May 15, 2018 1:37 am
Real name and title: Mr. KIHO KWON

### Re: Original Sample(O), Sample Mean(M), Standard Deviation(STDEV)

Then,
1)How can I calculate P values by using original sample, sample mean, standard deviation, and t statistics?

2) How can I calculate Confidence Interval of 97.5% the values of which are "n/a" as you can see below
Attachments
캡처.PNG (19.46 KiB) Viewed 617 times

jmbecker
SmartPLS Developer
Posts: 932
Joined: Tue Mar 28, 2006 11:09 am
Real name and title: Dr. Jan-Michael Becker

### Re: Original Sample(O), Sample Mean(M), Standard Deviation(STDEV)

1) You need to look into the t-table or use a function in another software like excel to compute p-values from t-values. The degrees of freedom is the number of bootstrap samples you have.

2) The easiest way to calculate confidence intervals is the percentile method, where you calculate the 2.5% and 97.5% quantile of the bootstrap parameter distribution that you have in the "Samples" output.
The following excel sheet provides an example how to calculate studentized confidence intervals for mediating models: https://www.pls-sem.net/app/download/15 ... 1485782413
It also demonstrates how to calculate p-values.
Dr. Jan-Michael Becker, University of Cologne, SmartPLS Developer
Researchgate: https://www.researchgate.net/profile/Ja ... v=hdr_xprf