A histogram is a visual display of statistical information to better understand how frequently certain values are present in a set of continuous data.

To construct a histogram, make a number line covering the entire range of your data, and then divide it into a number of equal chunks which is called bins.

Two common types of histograms is “independent variable” or “dependent variable” that is either plotted along the horizontal or vertical axis.

An example of a histogram and data is shown below.

## Constructing a Histogram

To construct a histogram from a variable, you first need to divide your data into intervals (bins), if using the above data we would get below result.

The split in our example is made so that each bin represents 0.02 starting from 24.40 and going up to 24.64.

Each bin includes the occurrences within that range, and there is no gap between them like in a bar chart. Any gaps seen would be due to an empty bin which indicates there were no occurrences within that interval.

## Bin Width in Histogram

There is no right and wrong in the width of the bins, but there is a rule of thumb not to make them too wide or narrow in width.

If the bin with is too narrow it shows too much individual data pattern to be easily seen. On the other hand, if the bins are too wide, it is not possible to see the trend of the data or do any analysis of it.

## Reading a Histogram

Due to the way histograms are constructed, it is easy to find the values for a range of data. If e.g. you want the values between the range of 24.46 – 24.56 from the example above, then you just add up the bins representing that area.

A histogram shows what proportions of a dataset fall within which ranges, and the shape of the histogram shows the shape of the data distribution.

## Histograms for Problem Solving

A histogram can be a very useful element in problem solving to visualise and analyse collected data as part of the problem definition or root cause analysis.

If you are interested in Histogram and data analysis, then our 8D Problem Solving Training might be interesting for you. The 8D Training is a detailed training on how to effectively solve problems and prevent them from reoccurring; Usage of Histogram is covered as part of the training.

Alternatively you can continue to our quality training page for an overview of the training we provide.

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