School Screening vs Full Diagnostic Assessment – What’s the Difference?

If you’re concerned about a child’s learning and wondering whether they might be dyslexic, it’s important to understand the difference between a school screening and a full diagnostic assessment. While both have their place, they serve very different purposes.

A school screening is usually a quick, computer-based check – often lasting no more than 20 minutes. It tends to focus on a limited set of skills and may not cover the areas now considered central to identifying dyslexia. Because it’s automated, results can be influenced by how comfortable the student is with using a computer, their focus on the day, and even their typing speed. Screenings can be helpful for flagging up general difficulties, but they rarely provide detailed insights or tailored recommendations.

In contrast, a full diagnostic assessment is carried out by a qualified dyslexia specialist and usually lasts around three hours. It explores a wide range of areas, including cognitive processing, attainment, and underlying ability. The process is flexible – additional tests can be added as the profile develops. What’s more, the assessor doesn’t just look at scores. They interpret the results in context, drawing on observations, background information, and input from parents and teachers to build a full picture.

A screening can be a helpful starting point, but it’s important to be aware that they can produce false negatives – where difficulties are missed – and occasionally false positives. More reliable screening options include tests like the New Test of Dyslexia (ToD) or the Dyslexia Portfolio, which are administered by a dyslexia professional rather than by computer. While no screening tool is perfect, these options offer more depth and accuracy at a lower cost than a full diagnostic assessment.

A full diagnostic assessment typically costs between £500 and £700. However, at SJB Assessments, based in Orpington, Kent, we offer parents peace of mind: if a child is not identified as dyslexic and they choose not to receive the full report, we will reduce the cost by £150. This ensures that families receive professional insight without committing to the full fee unless they feel it’s necessary. How to Get in Touch. If you’d like to find out more or book a dyslexia assessment, you can:

• Email Sarah directly info@dyslexiaservices.net

• WhatsApp: 07501 459 284

• Use the ‘Ask a Question’ form on our website: www.dyslexiaservices.net/assessments

• Or telephone for a chat

Please note: as Sarah is often busy assessing, tutoring or delivering training, she may not be able to answer immediately – but will always get back to you as soon as possible.