Screening tests have been developed based on research results that consistently show that a set of specific problems is very often related to a specific disorder or disabitlity. They should not be used to form a diagnosis, but to provide a tool to identify individuals who may need a more detailed specialist examination. Thus, screening is a method of differentiating those who are likely to have problems from those who are unlikely to have them. Those who are likely to have difficulties are most often referred for diagnostic examinations, and with confirmation of the disability they can start the treatment. The accuracy of screening tests is defined by sensitivity, specificity, and positive predictive value. Conducting screening is a process that is technically and ethically complex. To detect diseases and difficulties, the diagnostic test should be suitable for most people, diagnostic and treatment facilities should be easily accessible to all people, and the price should be acceptable. Screening should be performed continuously, so in ideal conditions, screening is not performed once. It should be a a repetitive process combined with monitoring a child's development. Some of the better known tests are the ASQ, Battelle Developmental Inventory Screening Test, BDIST, INPP screening method, developmental screening tests for children aged 4 to 7 - neuromotor, primary reflex tests, visual perception tests and visual - motor integrations, and developmental screening tests for children over 7 years - tests for assessing muscle coordination and balance, tests of aberrant reflexes, tests for assessing oculomotor functioning, tests for visual-speech recognition of sounds, tests for visual perception and visual-motor integration. In addition to screening methods and early detection of delays and deviations in language development, therapeutic procedures can be used that result in removing or stopping the progression of difficulties.