1.6. Testing for dyslexia: screening versus diagnosis
To detect dyslexia, one should first administer a screening test, and then conduct a more thorough examination that may lead to a diagnosis.
In this section, Professor Trude Nergård Nilssen explains how you can use the Dysmate tests for the screening and diagnosis of dyslexia.
Screening of dyslexia
So what does screening really mean?
In general, screening is a mass examination of a group of people, performed using a test — or other standardized research method — to detect the risk of a specific disease or condition.
The purpose of screening is to be able to initiate an intervention or begin preventative measures as early as possible.
Screening for dyslexia has exactly the same purpose as a routine check at the dentist.
The purpose is to detect a risk of dyslexia, or to detect possible dyslexia, so that one can explore further and implement preventative measures as early as possible.
Diagnosis of dyslexia
What is the difference between screening and diagnosis?
The primary purpose of screening tests is to detect risk factors for a condition in large numbers of individuals. For some people this screening process will indicate a need for further examination in order to confirm a diagnosis.
The same goes for dyslexia. When dyslexia is suspected, it is necessary to conduct further assessment:
▪️ Firstly, it is important to observe the individual´s reading and writing skills, and compare these skills to what would reasonably be expected for the age group or school year.
▪️ Secondly, it is important to examine whether reading and writing difficulties have resulted in linguistic-cognitive impairment. This will help us confirm the presence of dyslexia, and be more sure that weak reading skills are not due to other factors. Note that the linguistic-cognitive impairment can also be detected before formal reading instruction begins.
▪️ Thirdly, it is important to examine the presence of any family history of dyslexia.
These assessments need to be performed by a qualified professional and may or may not result in a formal diagnosis.
About the Dysmate tests
Research describing the tests´ measurement properties has been published in international peer-reviewed journals. The scientific articles explain the reliability, validity and norm basis of the Dysmate tests.
In short, the evaluations show that:
▪️ There is a strong correlation between the different tasks within each test, and that you therefore get a reliable picture of the test candidate’s skills in the different areas (“reliability”).
▪️ The statistical methods demonstrate that the Dysmate tests have a high degree of diagnostic accuracy. This was investigated by comparing the diagnostic results from the Dysmate tests with the “true” diagnosis in people who had already been examined and diagnosed with dyslexia (“validity”).
You can read the scientific article about Dysmate-C here (PDF available for download).
You can read the scientific article about Dysmate-A here (institutional login required).
How can the Dysmate tests be used in the context of screening and diagnosis of dyslexia?
The Dysmate screening tests can be used to detect the risk of dyslexia, and to detect possible dyslexia early. We recommend that individuals who are flagged up by the screening test also complete the Dysmate follow-up test.
The difference between the two can be briefly summarized as follows: the screening test creates an overview of the candidate’s reading and writing skills. The follow-up test creates an overview of the most well-known linguistic-cognitive markers of dyslexia.
If the test candidate receives a result below the normal distribution area on at least three of the screening sub-tests and on at least one of the follow-up sub-tests, there is a good chance that the individual might have dyslexia.
These results must of course be seen in connection with other information, such as family history.