Research has shown that very few studies examine teaching and learning vocabulary below fourth grade (NRP, 2000) as we have traditionally relied on implicit learning through storybook reading. The incidental exposure to words can increase the incremental learning of vocabulary often after a single exposure (Senechal and Cornell, 1993).
Yet recent research in vocabulary instruction points to the benefits of rich explicit instruction (Beck, Perfetti, and McKeown, 1982) that focuses on both definitional and contextual learning. The studies also show that storybook reading allows for active learning of vocabulary in and a rich context in which explore meanings. The early childhood comprehension technique of dialogical reading rely heavily on key vocabularies.
We have to decide what words to teach. Incidental vocabulary will occur but their are groups of words we focus our instruction when it comes to vocabulary.
Often in Reader's workshop models, literature circles with roles, or independent reading time students must select vocabulary words. This is not how incidental learning of words work. Students may not find challenging words, may select irrelevant words, or words they can not define.
Having students find and log their vocabulary words during often relies on teaching new words through context alone. This involves understanding if meaning is explicitly defined, implicitly defines, or stated in other text features like figures. Important skills to learn but not effective methods for rich vocabulary instruction.
Instead of allowing students to choose words and relying on context clues and dictionary skills to define these words teachers should intentionally select vocabulary words and build them into classroom discourse over a period of days through multiple exposure across multiple modes (Universal Design for Learning). You can not do this when students select words from independent reading books unless you have read and identified the words you want them to choose ahead of time.
Now reading builds vocabulary and we should encourage students to read independently while explicitly teaching comprehension monitoring for unknown words and how to define these words using context but students should not be in charge of determining the words they read.
Beck, McKeown and Kucan (2002) developed a three-tiered model as a general framework for vocabulary.
When choosing words for rich vocabulary instruction focus on those from tier II. The everyday words of tier I do not need to get taught. Academic language, the vocabulary and meaning making that pertains to the language of school and the tasks of reading and writing tasks associated with curriculum, draws on the second tier of words. This requires explicit rich instruction.
Other researchers (Hiebert, Goodwin, & Cervetti,2018) have applied computer analysis and modeling to evaluate massive text sets to identify a core set of vocabulary to teach. When analyzing books, 10% of the words contain 10% of rare vocabulary. These 300,000 words make up 88,000 word families. You will see very few in your life.
The other 90% of the words make up just 2,500 word families. A word family consists of its root, prefixes, suffixes and any other bounded or free morpheme that can change the meaning of the word.
In content areas these words get linked conceptually. A bat, to a cave, to the word habitat for example. In narrative texts vocabulary gets linked semantically such as scream and shriek.
T semantic, morphological,and multiple-meaning connections within the core vocabulary and tier II of the three tiered model of academic language means these words can not get taught in isolation. A teacher does not print out the word families in go down the list.
Tier I words, or 30% of the word families in core vocabulary do not get taught. When selecting words choose choose those that make connections. Explicitly teach the underlying systems and features of words you choose.