Bar graph v/s Histogram - by Parul sukhlecha-PGDM 2013027

DIFFERENCE BETWEEN BAR GRAPHS AND HISTOGRAM

BAR CHARTS:

A BAR graph, is a way of showing a comparison of values. It is a chart wherein each bar is in proportion to the value that it represents. Bar graphs are used to help organize data and information.
Here is how to read a bar chart:

§  The columns are positioned over a label that represents a categorical variable

§  The height of the column indicates the size of the group defined by the column label

HISTOGRAMS:

A histogram allows a visual interpretation of data by indicating the number of data points that lie within a range of values, called a class.

The frequency of data that falls within each class is depicted by the use of bar.

Like a bar chart, a histogram is made up of columns plotted on a graph. Usually, there is no space between adjacent columns. Here is how to read a histogram.

• The columns are positioned over a label that represents quantitative variable
• The column label can be a single value or a range of values.
• The height of the bar corresponds to the relative frequency of the amount of data in a class

The difference between bar chart and histogram:

§  Bar graphs measure the frequency of categorical data, and the classes for a bar graph are these categories. On the other hand, histograms are used for data that is at least at the ordinal level of measurement. The classes for a histogram are ranges of values

§  One implication of this distinction: it is always appropriate to talk about the skewness of a histogram; that is, the tendency of the observations to fall more on the low end or the high end of the X axis.

§  With bar charts, however, the X axis does not have a low end or a high end; because the labels on the X axis are categorical - not quantitative. As a result, it is less appropriate to comment on the skewness of a bar chart.