How does a diagnostician determine the likely root cause of a reading comprehension deficit when decoding is relatively strong?

• A. Focus solely on decoding strategies with phonics.
• B. Evaluate only phonological awareness.
• C. Use effectiveness of decoding to determine root cause.
• D. Investigate language processing, working memory, listening comprehension, vocabulary knowledge, and inferencing abilities; use targeted assessments to differentiate underlying skills.

Answer: (D)

When decoding is strong, the likely source of a reading comprehension deficit lies in language processing and related cognitive skills that support understanding text. Reading comprehension depends on more than word recognition; it relies on vocabulary knowledge, syntax and semantic processing, background knowledge, the ability to draw inferences, and working memory to hold and integrate ideas as you read. To determine the root cause, use a targeted battery of assessments that differentiate these underlying skills rather than focusing only on decoding. For example, evaluate vocabulary breadth and depth, morphological awareness, listening comprehension (to gauge language processing independent of decoding), inferencing abilities, and working memory or processing speed. The pattern of strengths and weaknesses across these areas reveals which underlying skills are limiting comprehension and guides targeted intervention, such as vocabulary development, semantic mapping, or strategy instruction for making inferences and summarizing.

Focusing solely on decoding strategies would miss a comprehension problem when decoding is already adequate. Evaluating only phonological awareness would ignore later-developing language and cognitive processes that drive understanding. Relying on decoding effectiveness to identify root cause is circular and inappropriate when decoding isn’t the limiting factor.