
Listen. I’m a big individual. I’m 6’2 and weigh more than I should.

This means I have big fingers. Not comically large, mind you, but the size you’d expect a 6’2″ guy to have.
This means that sometimes I have a hell of a time tapping on things on my phone.
Those little “x” buttons that you need to tap to get rid of an annoying pop-up ad is probably the most prevalent example.
These are called “targets” in the accessibility world. Things you click on that prompts some kind of action… and they aren’t too small on just phones, but on websites in your laptop browser too.
There’s an ENTIRE section about it in the Web Content Accessibility Guidelines (WCAG) International Standard. This is something you need to care about because your organization can be SUED for not meeting accessibility guidelines… and not only if you’re putting a dashboard on a public website, but it also applies to internal webpages (you’re gonna look at your intranet differently from now on).
What does the WCAG say about target (anything you expect people to click on, whether by mouse, finger, stylus, etc) size?
WCAG Level AA (The bare minimum to meet legal requirements):
The size of the target for pointer inputs is at least 24 by 24 CSS pixels.

WCAG Level AAA (The enhanced level that you should attempt to make your dashboard as accessible as possible re target size):
The size of the target for pointer inputs is at least 44 by 44 CSS pixels
Now, there are 2 main exceptions to these rules…
1. If the target is in a block of text, and the size of the text link is constrained by the size of the text (but you already know that you shouldn’t be making your text/labels/titles small right?)
2. If there is an alternative target (that is at least the minimum size) that does the same thing. Like, if instead of tapping a bar on a bar chart or a marker on a line chart (more on this below) to filter the data could be done by an alternative method, like a slicer or a filter in the Filter Pane.
I can pretty much GUARANTEE you that almost every dashboard you’ve seen has had targets that are significantly smaller than 24 by 24 pixels.
Let me show you what I mean.
This dashboard is on the Microsoft’s Power BI Data Stories Gallery, and is one of the dashboards in their “Top Kudos” section, which basically means it’s been upvoted a lot. Those Microsoft nerds love it.

To be frank, this is a *horrible* dashboard if you want to tell data stories with it. It’s NOT a dashboard that is designed to let an audience easily know what to pay attention to and what the key insights are.
It’s NOT a dashboard you give a CEO or Board or Senior Management team or ANYONE who wants key numbers / trends / stories easily. It’s an exploratory (interim) dashboard, for finding data stories, rather than presenting them.
So, let’s say that this dashboard has been built for exploration. How are it’s target sizes? Let’s text it out by adding a 24 x 24 square to it and see what things fail the minimum WCAG standards.
We’ll start at the top, with their trend buttons… and these are actually okay. The WCAG standards apply to rectangle or irregularly shaped targets, and the same size dimensions apply… at least 24 x 24 pixels is the minimum.

Next, we have the issue of the line chart beside these buttons. It’s not evident, but each one of these date points in clickable and will filter the rest of the page. They are *obviously* too small (especially if this is being viewed on a phone (which is a whole host of issues itself), BUT they’ve provided an alternative in the year and month slicers right above it.

This is where the good news end.
Just about every other clickable (non-text) target on the page is too small.

Especially the bubble map, with tiny little bubbles for some cities, and no alternate way to filter things by city (the Top 5 Cities by Sales chart in lower right doesn’t count as an alternative… not only is it only 5 of the cities, but the targets on that are too small as well).
The moral of the story here is, as usual… stop putting so much data on each of your dashboard pages. The more data you show your viewers at once the harder time they’ll have finding the data stories they need.
Using your dashboard becomes a CHORE when you design a dashboard like this. Too much data AND each chart (and target) becomes smaller as it’s squished onto the page.
Instead, think minimally and about your user. Give them those key numbers they need and then give them the ability to see more data (if they so choose).
In the above example, I’d keep those 3 blue boxes that summarize Sales, Profit, and Profit Ratio, but reduce just about everything else… showing just the top products and cities (and just the last year of data in that line chart).. but with each of these “top” charts having a (well-sized) button that lets them go to another page that shows more data about that metric.
Make everything bigger. Size matters.




























































