Decoding and Reading are two different things

Here's an ED Hirsch article which points out that children's ability to learn and expand their vocabularies precedes their ability to decode letters and words. If you want to establish a child's vocabulary at a young age, then you need to teach content: knowledge, science, history, art, and facts, in a parallel stream to teaching them decoding (like phonics) and encoding (writing and spelling.) The mechanics of reading for a young child make it harder to grasp the content of what they're reading--the mind is so busy puzzling out the sounds and the words that it has little left for understanding. Teaching content through out-loud reading can get kids the vocabulary and the knowledge they need to really be able to read.

Why Is There So Much Listening in the Core Knowledge’s Reading Program? « The Core Knowledge Blog