Theory & Evidence

The Diagnostic Evaluation of Language Variation – DELV™–Screening Test (ST) and DELV™–Norm Referenced (NR) test (DELV, 2018) is the only unbiased, standardized test, designed to identify speech and language disorders/delays in English-speaking children ages 4 to 9. Its extensive norming procedures make it appropriate for both mainstream and non-mainstream speakers, including those who speak African American English.

The DELV tests incorporate key insights of modern cognitive science uncovered through acquisition research into the surprising complexity of “simple” words and sentences found in everyday language. They reveal dimensions of language disorders rarely taken into account, and for purposes of unbiased testing, are not sensitive to linguistic and cultural variation.

• Syntax items designed to measure a child’s understanding of complex wh-questions, passives, and the use of articles (“the” and “a”) in different contexts.
• Pragmatics items that probe for what someone should say in a particular situation (communicative role-taking); the ability to link characters and events, and include references to mental states in simple stories (narrative); and the ability to ask the right question to obtain specific information (question asking).
• Semantics items that go beyond vocabulary to measure a child’s understanding of the relationship between words of the same meaning type (verb relationships; prepositions); the meaning of “every” in sentence contexts (quantifiers); and the ability to extract novel verb meanings from sentence contexts (fast mapping).
• Phonology items designed to assess a child’s production of consonant clusters in the initial and medial positions of words in the context of a sentence.

The unique features of the DELV allow for a profile of a child’s strengths and weaknesses, not just a diagnostic categorization. The DELV thus provides a non-discriminatory understanding of central aspects of language vital for success in early schooling and the transition to literacy.