This week’s source chart is a shocker. There’s very little right with this chart. The title is good, because it asks a question. After that it pretty much falls apart. The actual percentage value is very hard to see. The donut doesn’t help. The percent change circle is totally confusing. They also used a negative scale to size the circles which requires mental hurdles to overcome.
My makeover is at the top.
Comparing growth and decline between two time periods immediately cried out “Slope Chart”. It could have been a side-by-side bar chart, but I am not a fan of those. A dumbbell chart might have worked too, but showing the direction of time is a challenge. I tried Comet Charts to show this, unsuccessfully, a few years ago.
I really wanted a pure slope to work, with all lines within one pane.
However, this didn’t work for me. Too many of the lines were too close. I had to do callout labels for Television. The four lines along the bottom are all a little too close to each other for my liking.
Instead I resorted to a pane for each item. Here’s the version without shapes:
It’s still easy to compare the slopes of each line but not quite as easy. The cognitive load is a little higher this way. As you can see at the top, I chose to add icons. I did this to make it easier to identify each line without the requirement to move your eyes to the top of each pane. Icons are more appealing than labels. However, using icons can be a challenge: what’s a universally identifiable icon for “smart thermostat”? How do you tell the difference between a Smartwatch and Fitness Monitor icon?
We chose this week to stick to greyscale. Remaking this chart was straightforward. Because there are multiple panes, I don’t need to use colour to identify each product.
I added the annotations to help users read the slopes, if they’re not familiar with them. Being in greyscale this week was a good reason to soften the text to a very light grey. This helps the annotation disappear when you want to focus on the marks. If the labels were as black as the lines, it all gets too much: