In this post I am going to try to explain orthographic mapping. I will not be able to fully explain it because I am still adding to my understanding of it. When you read texts, books or publications from the experts in the Science of Reading, you may hear about a person’s orthographic lexicon and their sight word vocabulary. Understanding what is meant by those two terms will help you understand orthographic mapping a bit more.

First up, orthographic lexicon. This is simply an individual’s lexicon, which means a vocabulary (dictionaries are sometimes referred to as lexicons) of words that they recognize and can read on sight. They no longer have to sound them out, they recognize that string of letters as a word instantaneously EVERY time they see it. It is called an ORTHOGRAPHIC lexicon because ortho means right, correct or straight and the person reads these words correctly every time they see them. Graph means to write or draw, so again the person reads these words correctly every time they see them written. The suffix -ic simply means having to do with reminding us that the lexicon/vocabulary has to do with correctly read written words. So an Orthographic Lexicon is a person’s VOCABULARY or collection of words that they read CORRECTLY every time they see them WRITTEN down.

Secondly, we will cover what is meant by sight word vocabulary in the Science of Reading. If you have been teaching for any length of time you have likely heard of sight words. You may even remember learning “sight words” when you were in school. In these contexts “sight words” are actually just high frequency words. This means they are words that appear often in our language and if you can read these words you will be able to read the majority of texts you have to read. However, within the context of the Science of Reading sight word vocabulary refers only to a person’s orthographic lexicon, those words that an individual can read correctly and instantaneously on sight, regardless of context or font.

The process of getting a word from being a random string of letters to a word within a person’s orthographic lexicon is called orthographic mapping. The most enlightening thing about orthographic mapping, in my opinion, is that it is NOT based on sight. Unlike letter names and sounds that are learned by sight, we map words based on meaning. This is where that repurposing of language centers within the brain comes into play. When children or people are learning new words and orthographically mapping them (committing them to memory) they use the portions of the brains where the meanings and definitions of words are stored, not the sight parts of the brain. This explains why you may see someone familiar in the hallway, but not remember their name even though you can tell by sight that you know them. But, if you’ve orthographically mapped the word brown, you will automatically and correctly read it every time you see it. You won’t know it one day and forget it the next.

This understanding of the fact that we use meaning to get to words to “stick” instead of repetitions or visual/sight practice is the biggest game changer for me in understanding orthographic mapping. It means that if a child sounds out a word repeatedly, but has no understanding of the meaning of the word it will take longer to map the word. The meaning can be based on why the letters make the sounds they make in the word. For example, you may teach a student why circle has the /s/ sound for the first c (because it is followed by an i), but it has the /k/ sound for the second c )because it is followed by the consonant l). Or it can be based on the actual meaning of the word circle (that it is a round shape with no corners or sides).

There are several strategies that help readers map words more quickly. One is the use of sound boxes. This is particularly helpful for words that don’t sound like they are spelled like the word said. If you are using sound boxes with said you would need 3 boxes even though there are 4 letters. You only use one box for each sound regardless of how many letters it takes to spell it. The first box would be for the s that says /s/, the second box would be for ai that says /e/ and the third box would be for the d that says /d/. This strategy is actually to help students learn to spell words correctly. However, attaching the meaning of which sound is spelled with which letters can help the reader map the word more quickly. Stopping to discuss the meaning of a word that the reader does not know (how to read OR the meaning of) will also help with mapping. Thirdly, discussing the meaning of the whole sentence after figuring out a word that the reader could not read on their own, but knows the meaning of helps speed up orthographic mapping. A good reader needs 3-4 exposures to words to map them into their orthographic lexicon. Struggling readers need up to 20 or more. Studies have been done up to about 16 exposures, but then the difference in recognition starts to drop off so studies have not really been done on higher numbers of repetitions.

This is where and why having a strong verbal vocabulary is important to people as they are learning to read. As long as words remain simply strings of letter sounds with no real meaning to the reader, they will struggle to map the words and their reading rate (speed of reading) will remain slower. Another interesting thing to keep in mind before we leave this subject is that David Kilpatrick, one of the leaders in the study of the Science of Reading, says that we can work with young children to help them map words, but that mapping doesn’t really pick up until third and fourth grade. This is a tricky and possibly reassuring thought for some of our struggling readers in 2nd grade. It is vital that they have a strong and accurate knowledge of letter sounds and rules, but if they have a strong and complete phonics foundation and are still a slow reader it is likely that their orthographic mapping has just not picked up yet. This does NOT mean we should not be intervening for these students. It does mean that if speed is their only deficit, they may not be behind. Interventions should focus on phonics and phonemic skills to make sure that they are BOTH accurate AND automatic with all of those skills AND on building their verbal vocabulary through read alouds, class discussions and conversations. Their speed should be increasing. If it isn’t or if they are lacking in either ACCURACY or AUTOMATICITY in phonics or phonemic skills they need continued intervention on those things.