Here is our next attempt to improve the chart:

The first thing you'll notice is that we've changed the chart type. We now have a line chart, which means we can easily see each product's change over time. A line chart makes it possible to show that each product has its own dynamic. We can see how some revenue trends have changed. And there is a clearly defined time axis that runs along the bottom of the chart.

This chart is another improvement, but we can do even better. Look at the final chart, shown below:

We have changed the chart type again. We are now using a scatter plot with added trend lines. In this case, it's not the actual data that is the most important thing; the trends in the data are what we want to highlight, and that's what this type of chart does.

To further emphasize the message, we have added a chart title, a subtitle, and a vertical axis title. We've used the chart subtitle to clarify what the reader should see in the data (“Notice the strong upward trend for Product A”). The reader may or may not read the chart that way – they may instead focus on the rapid descent of Product C – but the point we want to make is clear.

Now you know what to expect as we continue our data visualization course. Let's move on to the next section – Key Elements of the Visualization Process, we'll learn the building blocks of data visualization, including how to identify types of variables and how to apply the data visualization process. It's an exciting journey, and one that you'll find rewarding!