I’m sure you’ve heard it said that a graph needs to be “immediately recognizable” or “understood at the snap of your fingers.” After all, “a graph is worth a thousand words,” right? But is this assumption true? Can you simply glance at a graph or chart and immediately understand it? Let’s do an experiment.

Sure, you see bars going up and going down. Maybe you noticed the gap where the fifth bar should be. But what is it showing? Different countries? States? Years? Months? You can’t tell—we need some labels along the horizontal axis.

Okay, that’s better. Now I know the data start in 2000-01 and end in 2022-23. But I still don’t know how tall the bars are. Do they extend to 10? 100? 1,000?

Now that’s better. We can easily see that the graph ranges from about 20 (ignoring the missing value in 2004-05) to around 55 in 2015-16. Still, we don’t know what these numbers indicate. Are they percentages? Dollars? Euros?

Whoa boy, now we’re getting somewhere! We now know that the bars show the number of games the Washington Capitals professional hockey team won each season from the 2000-01 season to the 2022-23 season. But we’re still not done! What’s going on in 2004-05? What changed that some years are higher than other years? For that information, we need some additional labels and annotations.

Love it! It’s now apparent that in 2004-05, there was full-year lockout and no games were played. And that dip in 2012-13? That’ a partial-year lockout. We also learn that the Caps won the Stanley Cup two years after the season in which they won the most games (56 in 2015-16).

Oh, and don’t forget, we can add a bit of highlighting to make that championship year even easier to see!

So, did you understand the graph “immediately,” “at a glance,” or “right away”? Or did you need help from the labels and annotation?

I focus a lot on text-in-dataviz in this newsletter because I think it’s one of the most important qualities for a good, effective graph. Understanding your message and what you want to tell your audience—and then how to do it—is so important to effective communication. Simply relying on the bars, dots, and lines in your graphs is not enough.