Histograms

A Histogram is a graphical display of data using bars of different heights.

It is similar to a Bar Chart, but a histogram groups numbers into ranges

And you decide what ranges to use!

You asked customers who bought one of the "Aurora" range of skirts how old they were.

The ages were from 5 to 25 years old.

You decide to put the results into groups of 5:

So when someone says "I am 17"
you add 1 to the "16-20" range.

And here is the result:

You can see (for example) that there were 30 customers between 6 and 10 years old

Histograms are a great way to show results of continuous data, such as:

But if your data is in categories (such as Country or Favorite Movie), then you should use a Bar Chart.

Frequency Histogram

A Frequency Histogram is a special histogram that uses vertical columns to show frequencies (how many times each score occurs):

Here I have added up how often 1 occurs (2 times), how often 2 occurs (5 times), etc, and shown them as a histogram.