A sight word is a word that, when encountered in print, is instantly recognized by the reader. Over time, proficient readers build an immense sight word vocabulary. But there are two ways to build that vocabulary, and one is far better than the other.
Those Sight Word Lists Your Child Brings Home
If your child's teacher sends home a list containing words like she, my, his, when, etc., when he is just learning to read and asks that you help him memorize them, this is done for a specific purpose. The reading curriculum hasn't yet gotten to the point where the phonics content of those words has been covered. For example, the sh in she might be covered next week, but the /ee/ sound of the letter e might not be covered for several weeks yet.
But to read even simple stories, or even short sentences, a lot of words like the ones above need to be learned. Hence the appearance of those sight word lists in your child's backpack. But there are two ways to learn them. One way is efficient and one way is inefficient, from the point of view of how it helps your child's reading.
The Efficient Route: Using the Phonics Content
Using phonics, your child first learns two phonics elements: The digraph sh represents the sound /sh/, and the letter e can be either the /e/ sound or the /ee/ sound. He sees the sh in she and says the sound /sh/, then adds either the /e/ sound or the /ee/ sound. Only the second option yields a recognizable word, she. From then on, he thinks of she in those terms although, and this is important, he might not yet recognize it on sight. That is, he has not yet converted it to a sight word.
The word she only becomes a sight word after your child has decoded it several times, a number varying across children. Each time he decodes she he is using a relatively slow dorsal path through the left side of his brain. But, at the same time, synapses are being constructed along a far faster ventral path on the left side. After one, five, ten, twenty or fifty successful decoding attempts, the synaptic route through the ventral path is finally completed.
From that point on, she is a true sight word that your child no longer has to decode. He sees she, the synapses fire along the ventral path, and he instantly knows the word without having to decode it. Put another way, he has hard-wired his recognition of she into his brain.
The key point here is that all of this is left-brain activity and research has shown that is typical of proficient readers. Relatively poor readers, on the other hand, tend to show a lot of right-brain activity when they read. So why is that?
The Inefficient Route: Rote Memorization
If your child learns to recognize the word she without using the phonics content, he must find another way, one possibly guided by you, his parent. You might, for example, make flash cards of his sight word list and show him the cards time after time until he finally says "she" consistently on seeing that card.
But what's going through his mind if he's not thinking /sh/+/ee/, she? We don't know, and it could be different for each child. For example, your child might be saying letter names "S, H, E, she" in his mind every time he sees she. Or he might be really creative and come up with various mnemonics, or memory clues. If he's doing both she and he in the same list, he might tie them together as a pair and know what she is because his sister is taller than he is (and she is longer than he). As for he, well, it's the other one.
For that matter, he might tie she to something he saw happen when he first studied the word. Maybe your female cat was sitting on your lap when you showed him the flash card and he thought, "Ah, she is sitting on Mom's lap." It's a silly mnemonic, sure, but remember, these are being devised by five-year-olds.
The Problem with Rote Memorization
Your child might have a great memory, and be able to memorize hundreds of words using whatever method he decides to use. There are two problems though.
First, there are tens of thousands of words, and very few people are capable of memorizing that much data without utilizing reliable clues (such as the phonics content of words, for example.)
Second, learning by rote memorization is right brain activity. This is why poor readers, many of whom were taught by sight word methods primarily, show a lot of right brain activity when reading. But that's also the side of the brain used for comprehending the story line, so reading this way interferes with comprehension. Switching back and forth between mnemonic clues for various words while trying to keep the storyline straight at the same time hurts comprehension.
The End Results
Obviously, many kids who've learned sight words end up reading just fine later, indicating that they have somehow managed to acquire a reading vocabulary of several thousand true sight words. This is likely because they eventually realize that almost every word has significant phonics content and start to use it while discarding earlier strategies. As they do that, they eventually build the same linkage through the ventral pathway that results in true sight word reading.
However, some don't, and become discouraged readers as both the complexity and the number of words they are expected to memorize to keep up with their classmates becomes too challenging.
A Word About Word Callers
A word caller is a child who knows the phonics of the words in a text and reads it fluently, but doesn't comprehend the meaning. It's a term usually used by people opposed to emphasizing phonics instruction, who claim that a child using a phonics approach can lack comprehension of what he's reading.
However, it's more likely that it's the whole-word reader, who is reading fluently while depending on a multitude of ways to recall the words he's reading, that is the word caller. He is putting so much effort into word retrieval that he has little capacity left for maintaining the story line. Given that this label is usually applied by teachers who don't advocate phonics instruction makes this explanation all the more likely.
A Word About Dyslexia (and Vision)
When a child can decode a word, but fails to automate it, that is, to turn it into a sight word, he's often labeled dyslexic. Ironically, it's blamed on a failure to process sounds, that is, on a phonological deficit.
But what if it's a visual deficit instead? The fast ventral pathway needs to be created by multiple successful decoding efforts, after which a connection is finally made and the word becomes a sight word in the child's reading vocabulary. So why isn't a decodable word becoming a sight word after dozens and dozens of successful decodings? It turns out that that same ventral pathway, the fast path, also deals with visual perceptual skills. It stands to reason that a child with poor visual perceptual skills might be having trouble developing the necessary neuronal connections along the ventral pathway to create a true sight word.
This could be for any of several reasons, such as poor visual memory, poor visual discrimination, or even poor vision skills such as both eyes not working well together. So, rather than jettisoning a phonics approach that most research has demonstrated to be not only effective, but the way proficient readers actually read, maybe we should pay more attention to root causes and get these children the help they need in improving their vision skills?
One More Problem with Sight Word Lists
If a phonics-based curriculum also relies on sight word lists, the child is getting a mixed message. That message? Some words are decodable and you should use their phonics content to figure them out, but many other very common words are not decodable and you should figure out a way to memorize them.
This is a very mixed message to send to a five-year-old, especially when it's unnecessary. Virtually every English word has a significant phonics content, and almost all are wholly decodable.
