Last week, I talked about the task completion rate for users with disabilities. Keeping track of this KPI involves real user testing. It helps me prioritise accessibility fixes and ensure that everyone can use the product effectively. It is however one of the more complicated metrics to track because of the logistics involved.
But not all metrics I track are complicated. The metric I use on this daily email for example is almost too simple to set up and it's also crucial for where I want to take this newsletter.
Readability score
Readability score, as a metric, measures how difficult your content is to read.
Every day, I sit down and write these emails. And of course I want to make sure I bring enough value to the table, but that'd be wasted if I used complex language that makes it hard for you to understand what I'm on about.
Readability scores help me ensure what I write is accessible to a wide audience. Using overly complex language can make it hard for people to engage. Especially for those with cognitive disabilities or non-native speakers like myself.
I write in simple phrases, avoiding complex grammatical structures and fancy words. I favour short paragraphs.
Even if it's just one sentence.
Here's the thing. Writing is like making music. You need to combine short sentences. Like this one. With longer sentences that give the entire paragraph voice, tone and personality. That's how you create music.
There's different ways to measure the readability score.
I use the Flesch-Kincaid reading level. This is a formula that assigns a score based on sentence length and syllables per word. The score ranges from 0 to 100, with higher numbers indicating easier reading. The numbers also translate to school grade levels.
I aim for a 8th to 9th-grade reading level. Disclaimer, this email goes a bit higher.
The other two scores I'm aware of are:
- SMOG (Simple Measure of Gobbledygook), which measures the number of complex words (those with three or more syllables) in a text.
- Gunning Fog Index, which estimates the years of formal education a person needs to understand a piece of text.
While aiming for accessible language, be careful not to "dumb down" the content to the point where it loses its value or professionalism. You can't prioritise clarity and simplicity over meaning.
I find readability scores helpful. But they shouldn’t be the only metric. For example, when writing technical content, you'll have to accept some complexity. In those cases, I aim to provide summaries or glossaries to help readers understand. I do this on my Accessibility Statement, Privacy and Cookies pages.
Tracking readability as a metric helps ensure that your content is clear, accessible and easy to understand for all users.
And setting it up as part of your CI with tests is not complicated at all. This way, you get early warnings for accessibility.