Standard deviation and standard error of the mean

In most clinical and experimental studies, the standard deviation (SD) and the estimated standard error of the mean (SEM) are used to present the characteristics of sample data and to explain statistical analysis results. However, some authors occasionally muddle the distinctive usage between the SD...

Full description

Bibliographic Details
Main Authors: Dong Kyu Lee, Junyong In, Sangseok Lee
Format: Article
Language:English
Published: Korean Society of Anesthesiologists 2015-06-01
Series:Korean Journal of Anesthesiology
Subjects:
Online Access:http://ekja.org/upload/pdf/kjae-68-220.pdf
Description
Summary:In most clinical and experimental studies, the standard deviation (SD) and the estimated standard error of the mean (SEM) are used to present the characteristics of sample data and to explain statistical analysis results. However, some authors occasionally muddle the distinctive usage between the SD and SEM in medical literature. Because the process of calculating the SD and SEM includes different statistical inferences, each of them has its own meaning. SD is the dispersion of data in a normal distribution. In other words, SD indicates how accurately the mean represents sample data. However the meaning of SEM includes statistical inference based on the sampling distribution. SEM is the SD of the theoretical distribution of the sample means (the sampling distribution). While either SD or SEM can be applied to describe data and statistical results, one should be aware of reasonable methods with which to use SD and SEM. We aim to elucidate the distinctions between SD and SEM and to provide proper usage guidelines for both, which summarize data and describe statistical results.
ISSN:2005-6419
2005-7563