the word complexity assessment • Yoast

We’ve always been proud of our readability analysis. It has not only helped us in writing readable text for the web, but also thousands of other users running Yoast SEO. Today, we’re introducing the latest addition to our readability analysis in Yoast SEO Premium: the word complexity assessment. Let’s explore what it is and how to use it to your advantage!

The word complexity assessment – currently in beta

As you can imagine from the naming, the word complexity assessment checks your text and highlights words that are complex according to our definition. It also tells you the percentage of words in your text that are complex. The more uncommon and complicated words you use, the harder it might be for your visitors to fully grasp your message. Thanks to the feedback in Yoast SEO, you can easily identify these complex words and change them accordingly.

It’s good to note that the feature is currently in beta. At the moment, the assessment only gives feedback for text in English. We think it’s a sensible decision to start with English since it’s one of the most wide-spoken languages in the world. With that said, we’ll be rolling out support for more languages in the upcoming updates of Yoast SEO Premium. Stay tuned!

Why we’re introducing this feature

The internet has enabled us to live in such an interconnected and fast-paced world. Nowadays, people constantly use the internet to search for all kinds of things. They also jump between websites to find the best possible answers. They may come to your site from Google, quickly scan your content and bounce back because your content isn’t easy to understand at a first glance. Next to that, if you have a website, especially one with content in English, it’s very likely to attract visitors from various places in the world.

For those reasons, we believe you should try to make your content as accessible and as easy to understand as possible. Of course, all without affecting the message you want to send. By making your content easier to read, you’re opening it up to a wider range of audiences. At the same time, easy-to-read content keeps your visitors engaged, making them stay longer on your site.

Previously, we had the Flesch reading ease score to give you a sense of how difficult a text would be to understand for users of different levels. It works well, and we’ve optimized many posts using this feedback. But we also find ourselves thinking: it’s not very actionable, isn’t it? Let’s say you have a post with an FRE score of 45 – which is considered difficult to read, and you want to make it easier to understand. How can you do that? Where should you start? With these thoughts in mind, we sat together at Yoast and came up with ideas to make our analysis more actionable. And the final product was the word complexity assessment.

If you want your text to be easier to read, reducing sentence length and the number of complex words you use is the way to go. With feedback from the word complexity assessment, you can quickly identify uncommon words and change them without having to spend time looking. In this sense, this feature is much more actionable because it offers you a direct measure of readability.

But what about the Flesch reading ease score?

You’ll notice that the Flesch reading ease score is no longer available in the readability analysis as it’s been replaced by the word complexity assessment. But no worries, it’s not going away anytime soon. We’ve just moved the feature into the Insight tab instead. Here, you’ll find the score and other insights into your content, such as the word count, reading time, and the prominent words in your text. But moving forwards, we won’t be using this assessment in the readability analysis.

It’s good to note that your overall readability score might change since the Flesch reading ease assessment has been removed and replaced by the word complexity feedback. But don’t worry that your readability score is drastically going to change. The word complexity assessment and Flesch reading ease measure similar things. So, if you had an overall green bullet before, that’s likely to stay that way.

For our users running the free version of Yoast SEO, you may also find your overall readability score to change due to the removal of the Flesch reading ease score.

A brief explanation of how the assessment works

So, how do we define whether a word is complex or not? As a starting point, we used datasets from several pieces of research that include both native and non-native participants. We then ran our own test and created a model that can discern between complex and non-complex words, based on the word length and how common they are.

As the final product, for the English language, we regard a word as complex if:

• It’s longer than 7 characters AND
• It does not appear in the top 5000 most frequent words AND
• It does not start with a capital letter.

For instance, the word ‘sensible’ can be seen as complex because it meets the conditions above. We exclude words that start with a capital letter as they either begin a sentence; or refer to specific individuals, locations, nationalities, titles, or events. Therefore, it would be impossible to replace these words.

We then use the following feedback strings to assess your text as a whole:

• Good (green bullet): you are not using too many complex words, which makes your text easy to read.
• Okay (orange bullet): a percentage of the words in your text is considered complex. Try to use shorter and more familiar words to improve readability.
• Bad (red bullet): same as the orange bullet, but triggered for cornerstone content.

We assign a threshold of 10% for the green bullet for the word complexity feedback. If less than 10% of the words in your text are complex, then your overall text can be considered easy to understand. On the other hand, if more than 10% of the words in your text are complex, then we’ll recommend you to use shorter and more common words.

How to use the assessment to your advantage

It’s pretty straightforward. The assessment works in the background, checking your text as you write. You’ll notice an eye icon next to the feedback in your sidebar. Clicking the icon will highlight words that are complex and uncommon. You can then decide for yourself what you want to do with these words.

In general, the feedback Yoast SEO gives may include words that are not complex at all for you, or for your audience. If that’s the case then, by all means, skip those suggestions. Next to that, there are many instances where it’s very difficult, or downright impossible to replace complex words with easier counterparts. Let’s say you’re writing a business report or a research summary that contains many specialized and niche-specific words. Most likely that the audience you’re writing for will understand those words, so you can safely skip our suggestions as well. Remember, no one knows your audience better than you! Regardless, we do want to advise you to try and make your text as easy to understand as possible.

The word complexity assessment, now in Yoast SEO Premium

The word complexity assessment is available in Yoast SEO Premium 18.9. Update your plugin now to get this feature! And stay tuned for support for more languages in our upcoming updates.

For our users running the free version of Yoast SEO, you will see this assessment in the readability analysis, but the option will be greyed out. You should consider upgrading to Yoast SEO Premium to unlock this feature. It’s powerful, actionable, and will surely help you in writing excellent content that your users will appreciate.