Autism Spectrum Disorder is not diagnosed using biological tests like medical conditions; instead a child is assessed using objective and subjective observations. This includes the looking at the child's developmental history, ability to process information, speech, language and behavior. Rating scales are useful because they clearly describe the child's behavioral pattern at the time of the assessment. This provides a baseline that can help measure the child's progress over the years. Autism assessment tools are commonly used by Occupational Therapists. However there are some assessment tools available that can be tested by teachers and other health professionals. There are many different types of assessment tools because each one has a different focus.

The Merrill-Palmer Scale of Mental Tests
The Merrill-Palmer Scale of Mental Tests (MPSMT) assesses visual-spatial skills in children from one and a half years through to six years old. The test is also non-verbal. Children with autism often have problems with visual-spatial skills, and verbal expression. This test is helpful for testing children who have difficulty expressing themselves verbally.

The Test of Nonverbal Intelligence (2nd ed.)
The Test of Nonverbal Intelligence (2nd ed.) (TONI-II) is also a non-verbal test that assesses the ability for children to think and problem solve. The assessment is used from age five years and up. It takes 10-15 minutes to administer the test, and from this it is possible to assess intelligence and reasoning skills of the child. This test can also be used for people with hearing impairments because speech and hearing is not required.