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Readability Scores – What They Mean and How we Audit Content

Written by Ben Leach on

We talk about clarity in written content a lot. It’s absolutely essential that you are able to communicate with your users effectively, making sure content is clear and easy to understand.

Understanding how content is audited is incredibly important for your own organisation. Auditing your own content is essential, and should be carried out regularly.

Why users struggle to understand some information you provide

Readers can get trapped in a particular sentence, no matter their literacy levels or disabilities. Most often, the problem is that the sentence is too long and complicated. As simple as that sounds, it’s quite a difficult problem to detect. After all, a sentence can be grammatically correct, but still hard to absorb. 

Low literacy levels

One reason why a user may not be able to understand a sentence or piece of content is down to their own literacy levels. In the UK, 14.9% of adults had literacy levels the same or lower than an 11-year-old. Incorporating complex language and sentence structure can often pose a challenge to those with low literacy skills.

Non-native language

Similar to those with low literacy levels, non-native speakers may struggle with complex vocabulary within sentences. Their English literacy is likely to be lower than many, especially if they are new to reading in English. Ensuring sentences use the correct grammar, and vocabulary is easy to understand, is important. They may also struggle with passive voice in sentences when an action is not given a clear owner. This is explained later in the blog. 

Cognitive processing difficulties

There are more than 1.5 million people living with learning difficulties in the UK according to research by Mencap. In the retired population (65+), this statistic increases to almost 2 in every 10 people having Mild Cognitive Impairments. 

Those with cognitive processing difficulties such as Dyslexia, ADD (Attention Deficit Disorder) and VPD (Visual Processing Disorder), Dementia, etc are likely to struggle to read content that contains long sentences and long words, grouped together in a series of long paragraphs. They may also struggle to read text that is centre-aligned or justified; starting text at the same position on each line is important 

There is a very useful simulation video of print distortions –  it shows what some people with dyslexia, and those with Irlen Syndrome, experience when reading text. 

How we audit content on a website

As part of our accessibility packages, we offer an audit for digital product owners to take advantage of. This involves assessing the technical and content accessibility of a digital service. 

We use a readability assessment tool to assess four key areas. If you are looking for a good content accessibility tool, we can recommend some. 

Percentage of long sentences

In written content, the key message can get easily buried in a long sentence. Ensuring your content is refined and easy to understand is vital in ensuring users can benefit from it. We consider 20+ words in a sentence to be long. We advise in all of our audits that long sentences should only make up 5% of your overall written content. 

Sometimes, long sentences can’t be helped, but often, using simple tricks can help make content become more understandable. For example, using bullet points instead of embedded lists, or removing unnecessary connectives, increases clarity. 

Average sentence length 

Whilst all sentences may not be long (20+ words), if most of your sentences are made up of 18 words per sentence, there’s a high probability that your content is still difficult to read. We assess a minimum of 100 pages on a site for content, advising that the average sentence length should be around 15 words. 

For a very similar reason to long sentences, a high average word count per sentence can mean that key messages are getting buried within your content. 

Passive Language

The use of passive voice within content can often mean that it becomes unclear, or the subject of the sentence has not been defined. The best way to communicate this is with an example of passive versus active voice. 

Passive voice is difficult to understand

Passive voice is usually when a subject (a person/organisation/thing) performing an action has not been defined, or is not defined first.. For example: 

“A new system was launched by the IT team.” 

In this instance, the subject is not clearly defined at the beginning of the sentence. It is not immediately clear who is launching the system until the end of the sentence.

Active voice is clearer 

When we write the sentence in the active voice, the subject becomes clearer. As they are the one carrying out the action, which is why it’s called the active voice. The sentence would change to: 

“The IT team launched a new system” 

The action being attributed to a subject, rather than the subject being attributed to an action can make many sentences easier to understand.

When can the active voice be used? 

There are many instances where passive voice is OK to use, but for clarity purposes, it’s best to include the subject first, unless they are: 

  • Unknown – we don’t know who performed the action. Eg. “The cave paintings were made thousands of years ago.”
  • Irrelevant – we don’t care who performed the action. Eg. “A brand new experimental solar energy facility will be built in Nottinghamshire.”
  • Purposefully vague – we don’t want to reveal who performed the action. Eg. “Mistakes were made”
  • You’re talking generally –  anyone can perform the action without regard to a specific subject. Eg. “Rules are made to be broken”
  • Your content’s focus is the specific action – the action is what you’re writing about, thus it is more important than the subject. Eg. “Insulin was discovered by researchers at the University of Toronto”

These are some examples of passive voice. When carrying out page audits, it’s essential you assess what the content is about, and whether passive voice is necessary. If it’s not, it is clearer if it is removed. 

Readability Scores (Flesch readability scale)

Finally, the main point we assess is the readability score of the content overall. We do this using the Flesch reading ease test. The equation seems complex (see below), but the goal is clear. The reading score attributes a total score out of 100 to the content based on how readable it is. 

The Flesch reading-ease test equation

206.835 – 1.015 (total words ÷ total sentences) – 84.6 (total syllables ÷ total words) 

However, don’t worry, there are plenty of websites and apps that are able to do this equation for you if you don’t want to do it manually (we can’t blame you!) 

The scores that are attributed to the content come with an explanation of how readable the content is:

0 – 10: Extremely difficult to read.

10 – 30: Very difficult to read. 

30 – 50: Difficult to read.

50 – 60: Fairly difficult to read. 

60 – 70: Plain English. Easily understood. 

70 – 80: Fairly easy to read. 

80 – 90: Easy to read 

90 – 100: Very easy to read. 

As organisations, we should all be aiming for the highest score possible in order to cater for the highest number of users. However, the section of WCAG 2.1 Guidelines relating to digital services being understandable state that content must be easy to understand, so a score of 60+ is considered according to the WCAG guidelines. 

Manual review required, readability scores aren’t everything 

It’s worth mentioning that you should approach content readability on a case by case basis. Carry out a manual assessment of the content. Readability scores should not be taken as gospel, but rather a helpful tool in defining areas for manual review. 

A great tool has been developed by Content Design London, called the Readability Guidelines. Described by many as a content writer’s bible on producing accessible content, this covers nearly all the basics when it comes to creating inclusive written content. 

It’s also worth thinking about your users when creating content. As content writers, we should always be referring back to our audience personas. It’s important to understand who will be reading the content, and why. For example, an academic dissertation published as part of a Biology Masters at University will most likely result in poor readability scores. This is not necessarily a bad thing, because:

  • Academic papers are often written in solely passive voice 
  • They will likely include complex terminology, which is required.
  • Methods and explanations may be understandably long. 
  • There are a lot of syllables in scientific terms. 

However, if you’re creating information for the general public, you should be taking note of readability scores. But we cannot stress this enough, always review the content. Test it with your users – does it make sense? Will the intended reader understand it? Is it necessary to include complex terms? 

If the answer is no to any of the above… just keep it simple. People like simple things. 

How to review and improve your website content 

You are best placed to understand the content on your own website. But, it’s valuable to know where your content needs improving, and how. 

Attributing readability scores to your written content allows you to review it manually and assess whether the content could be clearer and more accessible. We’re able to provide expert guidance, in our audits, to help you make your content more accessible. 

If you recognise that your content team requires upskilling when it comes to creating accessible content, we can help. We offer content editor accessibility training, helping your content writers and editors communicate with a wider audience more effectively.

If you’d like to know more, you can find more information on our accessibility packages in the links below.

Request information about readability assessment tools available

Request a Readability Tool Demo