What is the difference between screening, assessment, and diagnosis?
Dyslexia is not a disease — so it cannot be “diagnosed” in the same way that a medical condition can be determined. There is no blood test or genetic test that can show whether or not someone is dyslexic; a “diagnosis” is simply the opinion of a qualified professional.
Additionally, there is no uniformly accepted criteria for diagnosis, so professionals may disagree on whether or not a person is dyslexic, and on the labels they use to describe various types of dyslexia — or whether to use the word “dyslexia” at all.
In general, dyslexia is diagnosed on the basis of tests or evaluations used to measure a person’s learning characteristics and severity of symptoms.
A screening is generally a short, informal test which is used either to determine whether further testing or warranted, or to determine whether an individual is likely to be helped by a specific program. Licensed Davis providers use screening to determine whether or not an individual is likely to benefit from a Davis program.
The term assessment may sometimes be used to mean an informal screening, or it could be used to mean more extensive testing. It also is commonly used when the testing is focused only on ascertaining academic skill levels, such as a reading assessment.
Diagnostic testing usually means that the person will be given several different kind of tests, in an effort to get a full picture of their learning needs. Depending on the background and qualifications of the professional doing the testing, it may include tests related to vision and hearing as well as tests related to intellectual functioning and achievement.
Generally the professional will give a detailed written report summarizing the findings, and may also include recommendations as to the types of intervention or support that would be appropriate for the individual.
(Answer by Abigail Marshall)