Many children with reading disorders are unusually bright, and rely on memorization and guessing to read a large number of words. This allows them to "get by" without acquiring a strong foundation in basic decoding skills. By third or fourth grade, they often "hit the wall" with reading. What is Decoding?

Decoding is the ability to read words accurately based upon knowledge of phonetic rules and common word patterns. Early phonetic patterns include short vowels, regular long vowels (oa, ow, ai, ay, ea, ee, ue, ui, igh, ie, silent 'e') and irregular vowel digraphs (ow, ou, au, aw, oy, oi, ui, ew). Poor decoders often cannot accurately read these vowels in isolation or in nonsense words. Without a strong grasp of these rules and patterns, they focus primarily on consonants, and guess at words based upon the shape of the word or the letters in the word. This causes them to confuse or substitute similar appearing words (e.g. couch/coach, tall/tail, better/bitter, drown/drawn, party/pretty, jaw/ jay, thirsty/twenty), even when those word substitutions change the meaning of the sentence.

Poor decoders also guess at words based upon the context of the sentence or story. Weak readers rely heavily on guessing, whereas good readers use their decoding skills first, and only then assess whether the word they decoded makes sense within the context of the sentence.

Sight Words
What about sight words that can't be "sounded out"? Poor readers typically have a weak repertoire of common sight words, and poor visual memory for sight words. This weak visual memory also makes them poor spellers. Students with strong visual memory recognize sight words more readily, read more fluently and automatically, and spell more accurately.

Hitting the Wall
Many children "hit the wall" with reading in third or fourth grade. Up until that point, they have been able to get by with memorization and guessing strategies. By third or fourth grade, more advanced work attack skills are needed. Multi-syllabic words require decoding many small "word parts" and putting them together. These word parts are like nonsense words (per-pen-dic-u-lar). Poor readers are notoriously poor at reading small word parts and nonsense words. Weak phonological memory can also make it difficult for them to "hold" these word parts in memory in the correct sequence long enough to accurately assemble the word. Poor readers also lack syllable division and word attack strategies needed to decipher longer words. Knowledge of common affixes and patterns (such as "tion," "ture", "cious") is also weak.

Children who are lack these skills begin to fall further behind. As sentences become less predictable, guessing strategies become less reliable and inaccuracies increase. Reading becomes increasingly effortful. Fatigue and inaccuracies can begin to interfere with comprehension. Ineffective reading strategies and negative feelings about reading become ingrained, and are difficult to change. Third and fourth grade are a critical point in time for reading. At that point, children shift from "learning to read" to "reading to learn". Academic vocabulary and academic knowledge are built through reading. Poor readers are at risk in multiple subject areas if they are not able to improve their reading skills.