How to start using Tableau : Step 5: Make a line chart

This is a preview of the chart that we will be trying to make. It shows the average flight delay by month.

To start, we can create a new sheet by clicking the "New Worksheet" button in the lower left-hand corner of the screen.

To begin making the chart, drag-and-drop the "Date" variable into the “Columns” shelf. You should see a table appear with only one cell.

Next, drag the "Average Delay" variable into the “Rows” shelf. You should see a chart with a single dot appear.

Take a moment to consider this chart and to notice how Tableau has tried to helpfully interpret our drag-and-drop actions. The first thing to notice is that the chart only has one data point for the year "2013."

If we look at the "Date" variable in the columns shelf, we can see that a "YEAR()" function has been applied to the "Date" variable, indicating that Tableau has aggregated our data up to the year level.

To change this to show the month level, click on the "Date" variable, click on the white triangle, then click on the "Month May 2015" format.

You should now see a line chart!

We can also see that the "Average Delay" variable in the rows shelf has been aggregated using the "SUM()" function the same way it was in the previous chart example.

To change the way that this variable is being aggregated, click on the "Average Delay" variable in the "Columns" shelf, click on the white triangle that appears, and then click on "Measure (sum)," followed by "Average."

Lastly, name your chart so that you will easily be able to find it again. To do this, right click on "Sheet 2," click "Rename," and type "Seasonal Delay." Then press enter or click on something else to complete the naming process.