Dyslexia is a difficult disorder to diagnose. There are many factors the psychologist or other health professional reviews to diagnose the disability. The testing determines the child’s functional reading level and compares it to reading potential, which is evaluated by an intelligence test. All aspects of the reading process are examined to pinpoint where the breakdown is occurring. The testing further assesses how a child takes in and processes information and what the child does with the information. The tests determine whether a child learns better by hearing information (auditory), looking at information (visual), or doing something (kinesthetic). They also assess whether a child performs better when allowed to give information (output), by saying something (oral), or by doing something with their hands (tactile-kinesthetic). The tests also evaluate how all of these sensory systems (modalities) work in conjunction with each other.

The tests administered are standardized and are considered highly reliable. The child should not feel as if there is something wrong because testing is occurring. Many of the tests use a game-type or puzzle format which can help make the child feel more comfortable. Children should get a good night’s sleep prior to the testing and have a good breakfast. If the testing is done in a school setting, the teacher can prepare the child by talking about the person who will come and do special work with the child. With young children, the psychologist may visit the child’s classroom before the testing so that the child is familiar with him. Whether or not the testing is done at school, the parent may want to talk to their child about a new person coming to work with them. However, parents should not try to coach the child concerning the testing. It is recommended that parents not be present during the testing.

診斷讀寫障礙並不容易。 診斷時,心理學家或其他醫護人員需要考量很多因素。診斷測試會得出孩子的功能性閱讀水平,並將其與用智力測試評定出來的閱讀潛能比較。為了確定問題所在,閱讀過程中牽涉的所有方面,都會進行檢查。測試更會進一步評估兒童如何接收、處理及使用資訊。測試可評定出,孩子是通過聽取信息(聽覺)、觀察信息(視覺),還是用手直接處理事情(動覺)才能學得更好。同時,測試結果也會顯示出,孩子是以口語表達(口述),還是用手直接處理事情(觸覺及動覺),才能更好地表達(輸出)他要提供的信息。此外,測試會評估上述所有的感官系統如何彼此協同工作。

測試是標準化且高度可靠的。進行測試時,孩子應該不會自覺有甚麼問題,因爲測試內容大部分是以遊戲或拼圖的形式,以求讓孩子感覺輕鬆自在。測試前,孩子應有良好的睡眠及進食足夠的早餐。如於學校進行測試,老師可先告訴孩子將要來訪的是什麽人,並與孩子做些特別的事,讓孩子有點心理準備。對象是幼小的孩子時,心理學家也許會在測試前到訪孩子的課室,以讓孩子熟悉他。不過,無論測試是否在學校進行,家長也應該先與孩子談談,告訴他會有新來的人要與他做一些事情。然而,家長不應試圖為孩子將要進行的測試提供指引,也建議家長於測試期間不要在場。