Histogram – Counting Across Time

[Tutorial Tuesday]

Today we are going to talk about statistics.

Wait, come back . . . It’s not that bad. I promise.

Here is one tool that you can use to visualize data quickly. For the sake of our conversation, we’re going to visualize data across some period of time. In simplest terms, a histogram is a bar graph that shows you how much of something happens at any given interval. The purpose of a histogram is not just to be able to see how much something happens. Histograms show us, in a very quick way, the distribution of the values. Distribution means how the highest, and lowest, values are distributed. Where are the peaks and troughs? Once we can see this information we can start to make some decisions about what we might want to change.

Let’s say you are measuring how many cups of coffee you have each day. You may decide that you want to know the distribution of coffee consumption throughout the week. You would start by putting the days of the week along the bottom of your graph, and the number of cups of coffee along the vertical (y) axis.

Next, you simply have to plot the number of cups of coffee you have each day on the graph.

And finally, you create a bar up to each of these dots. From there you have your distribution.

You can immediately see which days you drink the most coffee, and which days are the lightest. If you are looking at this histogram from a personal health perspective, you might start to consider strategies to reduce coffee consumption on Mondays. But you don’t have to worry about Thursday or Friday. If you are looking at the same histogram from a coffee shop’s perspective, you might want to think about incentives that bring you in as a customer on Fridays. Histograms give you an immediate picture of how your data points are distributed across time or other elements. The picture will provide you with perspective and a place to start problem-solving and decision making.

Even though the type of graph that we are making today is called a histogram, it doesn’t always have to be across a time. You could have any value across the horizontal axis. It could be age, the number of times that you stop at the store or height. The vertical axis can be the measurement of whatever you are counting. The insight that you will gain each time is how the values are distributed across the horizontal (x) axis.

Find something to measure. Create your own histogram today. It will be fun. Aren’t you glad you read all the way to the end?