Decoding and reading comprehension: A test of the decoding threshold hypothesis.

This study supported the Decoding Threshold Hypothesis, which posits that the relation between decoding and reading comprehension becomes unpredictable when decoding falls below a threshold. As many as 38% of Grade 5 students and 19% of Grade 10 students in our sample were below the decoding threshold. These students did not make any progress in their reading comprehension score in the following 3 years; their peers did. Thus, the decoding threshold provides a way to identify students whose reading comprehension will likely remain poor unless their decoding can be improved to a level above the decoding threshold.