Vocabulary: Best Practices
Learn the impact of dyslexia on vocabulary acquisition and how to assess vocabulary both formally and informally. Find practical tips to increase vocabulary and help your student become a lifelong learner of words.
I still remember how I taught myself geography vocabulary when I was in 4th grade in the 60’s. We were told to look through magazines for pictures of geographical items like buttes, prairies, and mountains. No problem on the mountain. I had already been skiing at Mt. Holly! (More like a hill here in Michigan.) Prairies, I could figure out too, but a butte? Now that was a vocabulary picture challenge! I had a written definition of the words, but finding a picture in a magazine was mostly a search and guess challenge. Especially, since Reader’s Digest was the only magazine we had at home.
Now all a student needs to do is go to a computer, type in the word butte in a search engine and voila! No searching and wondering if this could possibly be a picture of a butte for our modern day students! They can get a plethora of butte pictures, along with detailed information about buttes and additional geographical highlights of canyons, cirques, cuestas, mesas, and even sinkholes! Because this is so simple, one would think that acquiring a large, rich vocabulary and having the grammatical skills for using those words would be effortless in today’s technological world.
However, while locating pictures is much easier today, acquiring a large, rich vocabulary appears to be just as challenging for students as it was 50 years ago, despite computer technology. And for a student who has dyslexia, it can be as difficult as looking for a picture of a butte in Reader’s Digest.
It is important to measure a student's understanding of vocabulary as early as possible. Research has demonstrated that students with reading difficulties will begin to fall behind in vocabulary because they do not read as much as their peers. And the gap only widens as they get older. Therefore, it is very important that these kids with reading problems are read to at a young age and as they get older have access to text via audiobooks and text-to-speech software.
Child language specialists have suggested that preschoolers learn about five new words a day (Kamil, 2004). By first grade, students will have a lexicon of about 6000 words. By the second grade, students learn an additional 2000 and 5000 words (Graves, Juel, & Graves, 1998). And as their reading and writing develops, on average students learn 3000 to 4000 words a year (Nagy & Anderson, 1984; Nagy & Herman, 1987). By the time students graduate from high school their vocabularies may reach 25,000 words or more.
To understand the magnitude of this, consider what learning 25,000 words would require in terms of instruction. To directly teach students even 3000 words a year would require teaching approximately 17 new words each school day (e.g., 3000 words/180 school days). Estimates vary, but reviews of classroom intervention studies suggest that, in general, no more than 8 to 10 words can be taught effectively each week. This means no more than 400 words can be taught in a year (Stahl & Fairbanks, 1986). Using a simple calculation, 3000 - 400 = 2600, produces the obvious conclusion that students must find ways other than direct classroom instruction to learn words.
So how do we help children and particularly children with dyslexia develop large listening and speaking vocabularies and learn to use them when reading and writing? Research shows that students need to encounter a word about 12 times or more before they know it well enough to help them comprehend it (McKeown, Beck, Omanson, & Pople, 1985). When students have enough encounters with a word, they’ll begin to use it in their writing and speech. That word then becomes a part of their personal vocabulary bank, or "repository."
We all know the vital importance of vocabulary for success in life. The Report of the National Reading Panel stated, "The importance of vocabulary knowledge has long been recognized in the development of reading skills. As early as 1924, researchers noted that growth in reading power relies on continuous growth in word knowledge" (pp. 4-15). The National Reading Panel also noted that comprehension development cannot be understood without a critical examination of the role played by vocabulary knowledge. Given that students’ success in school and beyond depends in great measure upon their ability to comprehend what they read, there is an urgency to provide instruction that equips students with the skills and strategies necessary for lifelong vocabulary development.
Vocabulary development becomes an even bigger challenge when a student is diagnosed with dyslexia. The negative experiences dyslexics have in learning to read may set in motion frustration and failure that continues throughout their academic years (Hart & Risley, 2003; Snow, Barnes, Chandler, Goodman, & Hemphill, 2000; White, Graves, & Slater, 1990). Because dyslexic students find reading difficult, they avoid reading. This avoidance reduces the opportunities they are exposed to, and thus, learning new words because more of a challenge. This sets in motion Stanovich’s (1986) "Matthew Effects" where ‘the rich get richer and the poor get poorer.’ In terms of vocabulary development, good readers read more, become better readers, and learn more words; poor readers read less, become poorer readers, and learn fewer words. In other words, if students with dyslexia read less and comprehend less, their vocabulary will not grow adequately. This has devastating consequences across the curriculum and limits post-secondary opportunities.
In the preschool years, language acquisition is focused on building oral listening and speaking skills. So for the first five years, children typically have not yet acquired a literate (reading and writing) vocabulary. Listening or receptive vocabulary, the largest, is made up of words the child hears and understands. By the time we reach adulthood, most of us will recognize and understand close to 50,000 words (Stahl, 1999; Tompkins, 2005). Speaking or expressive vocabulary is comprised of words we use when talking. Typically, receptive vocabulary is larger than expressive vocabulary. For example, if I say four words aloud, such as "dictionary, primary, lexicon, and revision" and ask a student which two go together (receptive language) many times, she can answer correctly (lexicon and dictionary); but it may be more difficult to express why those two go together.
We all have vocabulary that we "understand", i.e., receptive vocabulary. This includes our listening as well as our reading vocabulary. Our reading vocabulary is comprised of the words we understand when we read text. We can read and understand many words that we do not use in our speaking vocabulary.
Most often when we think of expressive vocabulary, we think of conversational speech. However, when we think of "using" vocabulary, we also need to think about writing. We generally find it easier to explain ourselves through speech. Not only was it our first form of communication that we learned, but we can use facial expressions and intonation to help get our ideas across. The listener can ask for clarification if something is not understood. Finding just the "right words" to communicate the same idea in writing when your 'listener' is not present can be more challenging. Emoticons :) are often used as a substitute to communicate intent. Our writing vocabulary is strongly influenced by the words we can spell. For daily use, most adults use a mere 5000 to 10,000 words for all their conversations and instructions.
These four aspects of vocabulary can be combined into our meaning/oral vocabularies (speaking and listening) and our literate vocabularies (reading and writing).
|Meaning /Oral Vocabulary||Literate Vocabulary|
Difficulties in listening (such as auditory comprehension, auditory memory, and /or auditory processing) will result in difficulties with learning language, which results in difficulties with learning to read and write. In turn, difficulties with speech (such as multiple misarticulations, language delays or disorders, autism, and Asperger’s syndrome) will also affect learning to read and write. Students who are limited in any one of these aspects are likely to be limited in other aspects as well and will need direct, effective, systematic, and most importantly, early and intensive intervention.
When children enter school, the focus becomes acquiring literate vocabularies. To access the printed words (and learn vocabulary), they must first be able to decode the text! Being able to translate or decode print into speech allows students to use their oral vocabulary to build their literate vocabulary. There is an abundance of research to show that an effective decoding strategy allows students to identify printed words accurately and then rapidly and automatically (Pikulski & Chard, 2003).
To decode, students need to acquire a basic knowledge about words called phonological awareness. They must learn ‘boundaries’ – meaning that words compose a sentence, syllables compose a word, and that individual sounds (phonemes) make up the syllables (and words). They must learn the alphabetic principle -- how the sounds of a word relate to printed letters. They need to learn phonics – that the letters (or a combo) represent a sound. Students with dyslexia are typically challenged when it comes to understanding phonological awareness, the alphabetic principle, and phonics. They then may have difficulty putting the sounds of a word together (i.e., blending). Students with dyslexia typically start off school with large speaking and listening vocabularies. But as they struggle with learning to read and write their vocabulary growth rate slows, in part due to a lack of access to the vocabulary.
One of the most persistent findings in reading research is that the extent of students’ vocabulary knowledge relates strongly to their reading comprehension and overall academic success (see Baumann, Kame‘enui, & Ash, 2003; Becker, 1977; Davis, 1942; Whipple, 1925). According to The Report of The Rand Reading Study Group (2002), research has shown that “many children who read at the third grade level will not automatically become proficient comprehenders in later grades” (p. 2). This drop in achievement at the third grade level appears very likely to be due to weaknesses in language development and background knowledge, which are required for reading comprehension (Pikulski & Chard, 2003).
Broad reading engages students in a wide variety of books. The more students read and the more often they read, the greater their opportunities for applying word-learning strategies and learning new vocabulary and therefore, increasing comprehension. A number of researchers have found that once students are reading on their own, the amount of time they spend reading is one of the best predictors of their vocabulary size (e.g., Herman, Anderson, Pearson, & Nagy, 1987; Miller & Gildea, 1987).
Beck, et.al. (2002) draw the research-based conclusion, “All the available evidence indicates that there is little emphasis on the acquisition of vocabulary in school curricula” (p. 15). Even students who develop large reading vocabularies may not use that vocabulary in their writing without teacher help and guidance. This relationship seems logical; to get meaning from what they read, students need both a great many words in their vocabularies and the ability to use various strategies to establish the meanings of unfamiliar words when they encounter them.
Four Levels of Vocabulary
The English language has a great many words, estimated to be between 450,000 and 750,000 words (Stahl, 1999; Tomkins, 2005). Since there are so many words to be taught – important words, useful words, interesting words, and difficult words – a hierarchy for teaching words has been suggested. Beck, et al. (2002) propose four levels or tiers of vocabulary. It is important to incorporate each of the following four levels of vocabulary in intervention, teaching, and assessment.
Level One consists of words that are used in daily language. They are spoken repeatedly and are used in different ways in our daily lives. Level One words are well-known. They are basic words such as sight words, words found in early readers, and the 5000 or so words we use for everyday conversation. Generally, as an English speaker, you don’t have to build Level One vocabulary because you already possess the basics (e.g., sad, funny).
Level Two words, however, are quite different from Level One. Often you need to be taught this vocabulary or you could pick it up from reading. This vocabulary is very important to educational success. This level consists of the high frequency words for more mature users. Words in this level are likely to be used in many academic courses and may have multiple meanings. They are often not taught since they appear “common”, but, in fact, they may not be well understood by many students (e.g., regardless, compromise).
Level Three words consist of vocabulary from specialized disciplines or occupations. This could include business or academic vocabulary (e.g., irascible, biogenetics).
The final level of vocabulary – Level Four – is different from all other levels. These words are infrequently used and are generally obscure. They don’t relate to any occupation and are not valuable in most work and social environments (Beck, et al., 2002). Some Level Four words are useful for teaching morphological clues (e.g., xanthodont - one who has yellow teeth, or noctuary - an account of what happens at night).
Beck and her colleagues recommend explicitly teaching Level Two and Three words. They estimate that there are about 7,000 words at Level Two and or 10,000 at Level Three.
Now that you’ve learned about the importance of vocabulary in a comprehensive education, it is important to learn how student vocabulary should be assessed. There are myriad standardized tests to evaluate your student’s vocabulary. Most of them assess one or two types of vocabulary tasks out of context. While helpful information may be gleaned from any of these assessments, you will also want to collect a language sample to see how your student uses vocabulary in connected language. It is useful to compare vocabulary use for spoken vs. written output as one may be stronger than the other. Comparing your student’s abilities between receptive and expressive tasks is advised since word-retrieval problems (i.e., accessing and saying a known word) may be a characteristic of your student’s dyslexia. Tests with multiple-choice or a more open-ended format (where a student can explain his word knowledge in his own words) generally yield higher scores and indicators of your student’s competence.
Below are a number of assessment tools for vocabulary. You will want to ensure that the measure is culturally sensitive (check the norms for this information). The following are some commonly used tests of both receptive (words that are understood) and expressive (words that one can verbalize) vocabulary:
- Receptive One-Word Picture Vocabulary Test (ROWPVT)
- Expressive One-Word Picture Vocabulary Test (EOWPVT)
- Peabody Picture Vocabulary Test (PPVT-4)
- The Word Test 2
- Subtest on the Comprehensive Evaluation of Language Fundamentals (CELF-4)
- Subtests of the Comprehensive Assessment of Spoken Language (CASL)
- Subtests of the Oral and Written Language Scales: OWLS
What the National Reading Panel Says About the Role of Vocabulary in Reading Instruction (Reprinted from National Reading Panel, 2000, p. 4-4) and recommendations for dyslexics:
- There is a need for direct instruction of vocabulary items required for a specific text. This is an essential accommodation for people with dyslexia.
- Repetition and multiple exposures to vocabulary items are important. Students should be given items that will be likely to appear in many contexts. Because dyslexics are less likely to have exposure to vocabulary from reading, making sure that they have repeated exposure to content and vocabulary words through oral language and listening is important.
- Learning in rich contexts is valuable for vocabulary learning. Vocabulary words should be those that the learner will find useful in many contexts. When vocabulary items are derived from content learning materials, the learner will be better equipped to deal with specific reading matter in content areas. All readers benefit from experiential learning of vocabulary in multiple contexts. Again, it is critical that dyslexics have access to the content through auditory channels (e.g., reading aloud, books on tape, print-to-speech software).
- Vocabulary tasks should be restructured as necessary. It is important to be certain that students fully understand what is asked of them in the context of reading, rather than focusing only on the words to be learned. Restructuring seems to be most effective for low achieving or at-risk students. Restructuring is essential for most people with dyslexia.
- Vocabulary learning is effective when it entails active engagement in learning tasks. Vocabulary instruction should include all channels for the dyslexic – auditory, visual, kinesthetic and must be taught with frequency (i.e., repetitions) in multiple contexts.
- Computer technology can be used effectively to help teach vocabulary. See computer programs below.
- Vocabulary can be acquired through incidental learning. Much of a student’s vocabulary will have to be learned in the course of doing things other than explicit vocabulary learning. Repetition, richness of context, and motivation may also add to the efficacy of incidental learning of vocabulary. As noted above, the dyslexic needs multiple exposures in multiple contexts.
Dependence on a single vocabulary instruction method will not result in optimal learning. A variety of methods was used effectively with emphasis on multimedia aspects of learning, richness of context in which words are to be learned, and the number of exposures to words that learners receive.
You can incorporate both incidental teaching and explicit instruction of vocabulary into every lesson or activity you do with students. Research is clear regarding instruction that will best develop large, useful vocabularies. The suggestions below describe oral language experiences that can be used at home and also at school to increase vocabulary.
- Ensure repeated exposure to vocabulary in different contexts. This increases word learning (Armbruster & Osborn, 2001). Creating multiple exposures to words (research tells us that students need to encounter a word at least 12 times or more) will allow students to increase their familiarity with the word and aid in comprehension of it.
- One caveat to learning new vocabulary is accurately pronouncing and spelling novel words. Teaching vocabulary should be paired with phonics and phonological processing activities. In particular, it is helpful to teach students to hear every sound in the word (through segmenting and blending tasks) and how to recognize syllable types to pronounce a novel word. Read more on phonemic awareness.
- Play games such as Outburst Jr., Catch Phrase, Password, Taboo, Upwords, Mad Gab, and category card games which reinforce newly learned vocabulary.
- The following games are suggested for spelling, which will teach words that then become new vocabulary:
- Boggle, Scrabble, Jargon, Unjumble: Stellar Speller from Discovery Toys, Word Flip from Discovery Toys, cross word puzzles, word scrambles, and word searches. See below for web pages associated with word puzzles.
- Play Jeopardy with categories/definitions/quotes from a given chapter.
- Play Wheel of Fortune using the words and sentences containing vocabulary words that the students created.
- Play a variation of Operator: one student draws a vocabulary word out of a hat, generates a sentence with it, and whispers it to the next student. The last student in the group writes down the sentence (focusing on good spelling) and gives the sentence to the student who generated the sentence. Peers may help each other edit the spelling or use of the word in the sentence. Ask students to categorize the words by meaning, number of syllables, or initial phoneme.
- Use index or flash cards. Repetition is a key strategy to learning vocabulary. These cards should incorporate: the word, its definition, its use in a sentence, as well as antonyms, synonyms, and roots.
- Encourage the use of prior knowledge, predictions about meaning, and refinements based on context to learn new words and read strategically (Baumann & Kame`ennui, 1991). An engaging way to do this in a group setting is to give each student a term and sample sentence or a definition of the term on a large card. Your students will have to infer the meaning from the sample sentences and will try to find the person with corresponding terms and definitions and stand by her. Then you can have the students adjust any mismatches by looking up each term in the glossary or an electronic speller.
- Discuss words and word meanings daily as they are encountered in texts, instruction, and conversation. Some students can connect a word with its referents in one or two exposures – a process known as fast-mapping. Other students many need multiple exposures (Dollaghan, 1985).
- Have students name common objects and use words to describe their shape and basic characteristics. This is thought to activate the student’s semantic representation via the expressive link. As more information is recalled about a picture or a form thus stimulating word form representation, naming becomes easier ( Hoover & Storkel, 2005).
- Ask students to name words in a category or find words in a category to increase concept knowledge (Honig, Diamond, & Gutlon, 2000).
- Script activities around a book or picture to engage students and enhance spoken language, in the areas of increased vocabulary and sentence length (Jordan, Snow & Porche, 2000; Richgels, 2004).
- Give examples of word usage in a variety of contexts along with the word definition to increase students’ understandings (National Reading Panel, 2000).
- Use rhyme because how a new word relates to existing words (neighborhood density) positively influences the speed of learning a new word (Hoover & Storkel, 2005).
- Have students act out sentences with adverbs ( e.g., Stand up quickly. Look at me angrily. Hum merrily.) which promotes active engagement with vocabulary learning (National Reading Panel, 2000).
- Give your students the opportunity to produce a poem, song, or rap about an element on the Periodic Table and record or perform it.
- Notice the common spelling and pronunciation patterns. Students can be taught to be word detectives searching for common features among related words (Cunningham & Stanovich, 1998).
- Teach students to read and comprehend unfamiliar words by using root words, synonyms, antonyms, word origins, and derivations. This can help establish the extremes of a word’s meaning. Knowledge of word parts is particularly useful when in a setting without access to a dictionary (Powell, 1986). Directly teaching word parts – affixes, base words, and word roots – greatly enhances vocabulary given that 60% of all English words have Latin or Greek origins (Armbruster & Osborn, 2001). See this list of common affixes (prefixes and suffixes) with meanings and examples.
- Read books aloud. This is an excellent way to focus on the rich and descriptive language. It’s not surprising that reading aloud has been found to increase the vocabularies of students from preschool through the elementary grades (Dickinson & Smith, 1994; Penno, Wilkinson, & Moore, 2002; Robbins & Ehri, 1994; Stahl, Richek, & Vandevier, 1991).
- Explicitly teach specific words and word-learning strategies. Research indicates that the intentional, explicit teaching of vocabulary can add words to students’ repertoires (see Tomeson & Aarnoutse, 1998; White et al., 1990) and improve reading comprehension (see McKeown, Beck, Omanson, & Pople, 1985; Stahl & Fairbanks, 1986). Intentional, explicit teaching of specific word meanings and of word-learning strategies is especially important for those students who have not developed the decoding and comprehension skills necessary for wide reading (National Reading Panel, 2000).
- Compare and contrast two terms, such as annelida and mollusca (two animal phylums).
- Ask your students to write a letter to the editor or an elected official, petitioning for a change in their community or state. Each letter must have a minimum of 8 descriptive words and 5 active verbs. Show a letter to the editor as an example.
- Color code words in a textbook or novel using a highlighter. Assign a color to adjectives, adverbs, and conjunctions. Once the highlighting is completed, ask your students to incorporate 2 new adjectives, adverbs, and conjunctions into their written summary of what they read.
You’ve heard the old adage, "Give a man a fish; you have fed him for today. Teach a man to fish; and you have fed him for a lifetime." While pre-teaching, active learning, and multiple exposures to vocabulary are essential to a student with dyslexia, it is not feasible or sustainable to do this across the curriculum and keep up with pace of the classroom. Therefore, one of the most strategic uses of your time is to help your students learn how to learn vocabulary. Here are some ways to do just that:
- Develop your students’ meta-cognitive skills for becoming word detectives. When they encounter an unfamiliar word, teach your students to use background knowledge, morphology, and the clues in the sentence to infer the meaning.
- Teach self-advocacy skills to ask for clarification when an unfamiliar term is used in classroom directions or lectures.
- Explicitly teach students to navigate their textbooks including the glossary, index, headings, subtitles, captions, tables, boldface words, review questions, etc. Show your students how to preview key words before reading and to look up their meanings.
- Create personal dictionaries (this can be done electronically or with good old-fashioned notebooks). Each novel word should be recorded and the student should infer the meaning from the context and then look it up in the glossary, dictionary, or electronic dictionary to see if she was correct. Each week, the student should select 10 of these new words to incorporate into her writing for that chapter.
- Give your students electronic talking dictionaries to use. They will not struggle so much to look up the words and will be more apt to use them. These dictionaries will help your students accurately pronounce the words as well. Earphones can be plugged into these so that they are not disruptive to the rest of the class.
- Teach your students to go straight for the thesaurus when they’re looking for a word. It will be likely be faster if they use an electronic thesaurus such as the ones here. (This will help them to pronounce the word as well.)
- Place posters around your classroom that help to expand vocabulary. Visual representations will make targeted vocabulary more salient.
- Garner your students’ interest through electronic tools.
- Find free flashcards and pronunciations for common SAT/ACT words.
By developing your students’ vocabulary, you have not only set up your students for success in school, you have given them the tools they need to become lifelong learners of words--philologists in the making! You have invested in them so that they can reap the dividends of a robust semantic repertoire in every arena of life.
The National Reading Panel (2000) cited computer technology as a promising technique for increasing vocabulary. The programs listed here provide opportunities to become familiar with words by drilling and practicing with them. This will help students with reading fluency and comprehension, but may not necessarily carry over to their expressive language use. The following are some programs that can support vocabulary learning.
This is a multi-lingual visual dictionary that creates a word web and defines words based on parts of speech.
Lingro is a very helpful tool that turns all the words in any website or digital text into a clickable dictionary and translates text into 12 different languages.
Generate your own word puzzles, crosswords, and cryptograms from your own personalized list of words. Discovery Education Puzzlemaker is a great resource for extra activities to solidify newly learned vocabulary.
This tool uses photographs of words in the real world to help you visually explore them.
RhymeZone is a simple website that will generate a list of rhyming words, sorted by number of syllables, for any word. Users may also look up definitions, synonyms, and more.
This online interactive English dictionary and thesaurus helps you find the meanings of words and draw connections to associated words.
TagGalaxy creates a 3D orbiting galaxy of words and their associations. Click on any word to move it to the center of the galaxy, then click again and watch the globe populate with images from Flickr.
Copy and paste text into the box and this tool generates a word cloud to identify the key vocabulary. You can sort words by content area.
Visuwords is a dictionary and a thesaurus that’s a great resource for writers! It allows the user to look up words to find their meanings and associations with other words and concepts. The user can produce word diagrams to see how words associate.
Using grade level puzzles, thematic games, and word activities, this site offers a variety of resources to aid in vocabulary instruction.
Place text into a box and then press "sift" to create a word cloud in which most frequently used words appear larger in size.
Teachers can sign up for a free account and create word lists to support written text. With a click of a button, students can access dictionary information and create flash cards for review.
Armbruster, B.B. & Osborn, J. (2001) Put reading first: The research building blocks for teaching children to read: Kindergarten through grade 3. Jessup, MD: National Institute for Literacy.
Baumann, J. F., Edwards, E. C., Boland, E. M., Olejnik, S., & Kame‘enui, E. (2003). Vocabulary tricks: Effects of instruction in morphology and context on fifth-grade students’ ability to derive and infer word meanings. American Educational Research Journal, 40(2), 447-494.
Beck et al. (2002) In Pikulski and Templeton 2004, Teaching and Developing Vocabulary: Key to Long-Term Reading Success, Houghton Mifflin Company.
Dollaghan, C. (1985). Child meets word: “Fast-mapping” in preschool children. Journal of Speech and Hearing Research
Dickinson, D. K., & Smith, M. W. (1994). Long-term effects of preschool teachers’ book readings on low-income children’s vocabulary and story comprehension. Reading Research Quarterly, 29, 104-122.
Graves, M. F., Juel, C., & Graves, B. B. (2004). Teaching reading in the 21st century (3rd ed.). Boston: Allyn & Bacon.
Hart, B., & Risley, T. R. (2003). The early catastrophe: The 30 million word gap by age 3. American Educator, 22, 4-9.
Herman, P. A., Anderson, R. C., Pearson, P. D., & Nagy, W. E. (1987). Incidental acquisition of word meanings from expositions with varied text features. Reading Research Quarterly, 23, 263-284.
Honig, B., Diamond, L., & Gutlohn, L. (2000). Teaching reading sourcebook for kindergarten through 8th grade. Novato, CA: Arena Press.
Hoover, J.R., & Storkel, H.L., (2005). Understanding word learning by preschool children: Insights from multiple tasks, stimulus characteristics, and error analysis. Perspectives on Language Learning and Education, 12(3), 8-12.
Kamil, M. L., & Hiebert E. H. (2004). The teaching and learning of vocabulary: Perspectives and persistent issues.
McKeown, M. G., Beck, I. L., Omanson, R. C., & Pople, M. T. (1985). Some effects of the nature and frequency of vocabulary instruction on the knowledge and use of words. Reading Research Quarterly, 20, 522-535.
National Reading Panel. (2000). Report of the National Reading Panel: Teaching children to read. Washington, D.C.: National Institute of Child Health and Human Development.
Nagy, W. E., & Anderson, R. C. (1984). How many words are there in printed school English? Reading Research Quarterly, 19, 304-330.
Nagy, W. E., Anderson, R. C., & Herman, P. A. (1987). Learning word meanings from context during normal reading. American Educational Research Journal, 24, 237-270.
Pikulski, J.J. and Templeton, S 2004, Teaching and Developing Vocabulary: Key to Long-Term Reading Success, Houghton Mifflin Company.
Pikulski, J.J., and Chard, D.J. (2003). Fluency: Bridge from decoding to reading comprehension. Boston, MA: Houghton Mifflin Company.
Stahl, S. A. (1999). Vocabulary development. Cambridge, MA: Brookline Books.
Stahl, S. A., & Fairbanks, M. M. (1986). The effects of vocabulary instruction: A model-based meta-analysis. Review of Educational Research, 56, 72-110.
Stanovich, K. E. (1986). Matthew effects in reading: Some consequences of individual differences in the acquisition of literacy. Reading Research Quarterly, 21, 360-407.
Snow, C., Barnes, W. S., Chandler, J., Goodman, I. F., & Hemphill, L. (2000). Unfilled expectations: Home and school influences on literacy. Cambridge, MA: Harvard University Press.
Tomeson, M., & Aarnoutse, C. (1998). Effects of an instructional programme for deriving word meanings. Educational Studies, 24, 107-128.
Rand Reading Study Group. (2002). Reading for understanding: Towards an R&D program in reading comprehension. http://www.rand.org/pubs/monograph_reports/MR1465.html
White, T. G., Graves, M. F., & Slater, W. H. (1990). Growth of reading vocabulary in diverse elementary schools: Decoding and word meaning. Journal of Educational Psychology, 82, 281-290.
For more on understanding vocabulary and semantic mapping, check out Reading Rockets' List-Group-Label article.