StATS: What is a descriptive statistic?

Descriptive statistics are numerical summaries from a sample that characterize that sample without any effort to test a particular hypothesis.

Examples

In a study of enteral feeding at an ICU, the abstract mentions:

Four-hundred-and-three eligible patients had a total of 3,526 records of feeding days. The desired intake was successful in 52% (1,842 of 3,526) of feeding days. The percentage of successful feeding days increased from 39% (124 of 316) on day 1 to 51% (112 of 218) on day 5. Average ideal protein intake was 54% (95% confidence interval (CI) 52 to 55), energy intake was 66% (95% CI 65 to 68) and volume 75% (95% CI 74 to 76). Daily enteral feeding practice on the ICU: attainment of goals and interfering factors. JM Binnekade, R Tepaske, P Bruynzeel, EMH Mathus-Vliegen and RJ de Hann. Critical Care 2005, 9:R218-R225. [Abstract] [Full text] [PDF]

The percentages and averages mentioned above are descriptive statistics.

In a study of public awareness of Japanese government policies on organ transplantation, the abstract mentions:

A relatively large percentage of people became aware of the issue when government actions were initiated, and many increasingly formed their own opinions on the policy in question. However, a significant number (43.3%) remained unaware of any legislative efforts, and only 26.3% of those who were aware provided positive appraisals of the policymaking process. Furthermore, a majority of respondents (61.8%) indicated unwillingness to participate in future policy discussions of bioethical issues. Public appraisal of government efforts and participation intent in medico-ethical policymaking in Japan: a large scale national survey concerning brain death and organ transplant. Hajime Sato, Akira Akabayashi and Ichiro Kai. BMC Medical Ethics 2005, 6:1. [Abstract] [Full text] [PDF]

The percentages mentioned above are descriptive statistics.

This page was written by Steve Simon while working at Children's Mercy Hospital. Although I do not hold the copyright for this material, I am reproducing it here as a service, as it is no longer available on the Children's Mercy Hospital website. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: Definitions.