Pub. date: 2008 | Online Pub. Date: November 27, 2007 | DOI: 10.4135/9781412953948 | Print ISBN: 9781412928168 | Online ISBN: 9781412953948| Publisher:SAGE Publications, Inc.About this encyclopedia
A histogram is a pictorial representation of the information in a frequency distribution or a relative frequency distribution of a data set. Histograms are used to display information about continuous variables and typically require grouping data into classes; this feature distinguishes it from a bar graph, which is primarily used for categorical or discrete data with a limited number of categories that do not require further grouping. A histogram displays the overall pattern and deviation of the data, but due to the necessity of grouping data into classes, it is not an exact representation of the data values. Histograms are most often created using computer software but may also be created manually. To make a histogram of a data set, proceed as ...