Descriptive statistics

The descriptive statistics is an important measure of statistics that is used to describe different features of a data set of a particular study. The primary objective of estimating descriptive statistics is to offer a brief summary of selected sample. The measure of descriptive statistics is done for a particular study. In combination with graphical analysis, descriptive statistics constitutes a major component in most of the quantitative data analysis technique.

The descriptive statistical measure is somewhat different from that of inferential statistics. The descriptive statistics is related to description of data that has been collected for the study. Inferential statistics in contrast involves drawing conclusion from the selected sample. Descriptive statistics are generally used for presenting quantitative data in a simple way. Different variables are present in a study. The descriptive statistics are used to break the numerous amount of data into the simple form. There are three main areas that are investigated through descriptive statistical measure. These are – nature of distribution, measures of central tendency and measures of dispersion.

The distribution: The distribution of a data set is the summary indicating frequency of single values within the range of a particular variable. A simple table of distribution lists all the values recorded against number of persons or the units each one of them had. For example, the easiest way to describe distribution of student in a university depending on year of study is to determine the either percentage of student or number of students.

The measures of central tendency: The different measures related to central tendency involves determination of values at center of the distribution. Three main central tendency measures are mean, median and mode. Mean which is average of the collected samples is the most common method in the central tendency measures. The median value indicates the exact middle value in the given set of values. Other important central tendency measure, mode accounts the value that occurs most frequently.

Dispersion

Dispersion is the measure that is used to explain spread of values in a distribution around the central tendency. The common measures of dispersion are range and standard deviation. Range is computed as a difference between maximum and minimum value. The measure of standard deviation shows how other values of the distribution differ from the mean value.

Descriptive statistics is needed to describe main features of a data set. It is very important for analyzing quantitative data. This is because it is difficult to present the raw data and understand the data is showing. This is especially the case for large data. Descriptive statistics provide a composite measure to present the data set allowing simple interpretation of the given data. Descriptive statistics by providing simple summary measures or graphical analysis make basis of quantitative data analysis in most cases. In a research study, the researcher may need lot of measures or the researcher may measure large number of people on a measure. Descriptive statistics provides a sensible way of analyzing and understanding large amount of data.