Share on Facebook Share on Twitter Email
Answers.com

Descriptive statistics

 
Sci-Tech Dictionary: descriptive statistics
(di′skrip·tiv stə′tis·tiks)

(statistics) Presentation of data in the form of tables and charts or summarization by means of percentiles and standard deviations.


Search unanswered questions...
Enter a question here...
Search: All sources Community Q&A Reference topics
Business Dictionary: Descriptive Statistics
Top

Quantifying or summarizing data without implying or inferring anything beyond the sample. See also Inferential Statistics.

Dental Dictionary: descriptive statistics
Top

n.pl

Statistics used to describe only the observed group or sample from which they were derived; summary statistics such as percent, averages, and measures of variability that are computed on a particular group of individuals.

Geography Dictionary: descriptive statistics
Top

As opposed to inferential statistics, which predict the state of a population from a sample, descriptive statistics, as the name suggests, draw on complete surveys of the dataset to summarize a state which exists at the present (or existed in the past), using means, medians, modes, standard deviations, correlations, and so on.

Thus, a shopping centre survey which included every user of that centre, rather than a sample, would draw on descriptive statistics.

Sports Science and Medicine: descriptive statistics
Top

Statistics that summarize the characteristics of a particular sample such as the attitude of a group towards aggression. Compare inferential statistics.

Wikipedia: Descriptive statistics
Top

Descriptive statistics are used to describe the main features of a collection of data in quantitative terms. Descriptive statistics are distinguished from inferential statistics (or inductive statistics), in that descriptive statistics aim to quantitatively summarize a data set, rather than being used to support inferential statements about the population that the data are thought to represent. Even when a data analysis draws its main conclusions using inductive statistical analysis, descriptive statistics are generally presented along with more formal analyses, to give the audience an overall sense of the data being analyzed.

Contents

Common uses

An example of the use of descriptive statistics occurs in medical research studies. In a paper reporting on a study involving human subjects, there typically appears a table giving the overall sample size, sample sizes in important subgroups (e.g. for each treatment or exposure group), and demographic or clinical characteristics such as the average age, the proportion of subjects with each gender, and the proportion of subjects with related comorbidities.

In research involving comparisons between groups, a major emphasis is often placed on the significance level for the hypothesis that the groups being compared differ to a greater degree than would be expected by chance. This significance level is often represented as a p-value, or sometimes as the standard score of a test statistic. In contrast, an effect size is a descriptive statistic that conveys the estimated magnitude and direction of the difference between groups, without regard to whether the difference is statistically significant. Reporting significance levels without effect sizes is often criticized, since for large sample sizes even small effects of little practical importance can be highly statistically significant.

Examples of descriptive statistics

Most statistics can be used either as a descriptive statistic, or in an inductive analysis. For example, we can report the average reading test score for the students in each classroom in a school, to give a descriptive sense of the typical scores and their variation. If we perform a formal hypothesis test on the scores, we are doing inductive rather than descriptive analysis.

Some statistical summaries are especially common in descriptive analyses. Some examples follow.

See also

External links


 
 

 

Copyrights:

Sci-Tech Dictionary. McGraw-Hill Dictionary of Scientific and Technical Terms. Copyright © 2003, 1994, 1989, 1984, 1978, 1976, 1974 by McGraw-Hill Companies, Inc. All rights reserved.  Read more
Business Dictionary. Dictionary of Business Terms. Copyright © 2000 by Barron's Educational Series, Inc. All rights reserved.  Read more
Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.  Read more
Geography Dictionary. A Dictionary of Geography. Copyright © Susan Mayhew 1992, 1997, 2004. All rights reserved.  Read more
Sports Science and Medicine. The Oxford Dictionary of Sports Science & Medicine. Copyright © Michael Kent 1998, 2006, 2007. All rights reserved.  Read more
Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Descriptive statistics" Read more