Vocabulary knowledge is important to reading because the oral and written use of words promotes comprehension and communication. The three primary types of vocabulary are oral vocabulary, which refers to words that are recognized and used in speaking; aural vocabulary, which refers to the collection of words a student understands when listening to others speak; and print vocabulary, which refers to words used in reading and writing. Print vocabulary is more difficult to attain than oral vocabulary because it relies upon quick, accurate, and automatic recognition of the written word. Furthermore, the words, figures of speech, syntax (the grammatical arrangement of words in sentences), and text structures of printed material are more complex and obscure than that of conversational language [2]. A few studies have suggested that vocabulary instruction leads to improved comprehension [3].
In addition to distinctions between oral, aural, and print vocabulary, vocabulary is categorized according to whether it is typically used in an informal or formal setting. Vocabulary used in a formal, educational setting is referred to as academic vocabulary [4]. Researchers who investigate academic vocabulary knowledge typically categorize words into three areas:
- high-frequency, everyday words (e.g., building, bus driver, eraser, etc.);
- non-specialized academic words that occur across content areas (e.g., examine, cause, formation); and
- specialized content-area words that are unique to specific disciplines (e.g., ecosystem, foreshadowing, octagon) [5].
Two important skills that are associated with vocabulary development are word identification and word analysis [6]. Word identification or decoding refers to the ability to correctly decipher a particular word out of a group of letters.
Word analysis is defined as the process involved in understanding the letters, sounds, and roots, prefixes, and suffixes that make up words, to enable a student to understand and use those words [7]. Word knowledge also includes syntactic awareness or awareness of the grammatical use of a word, such as the part of speech represented by a word [8]. We assume that students successfully analyze a word when they articulate its meaning and use it correctly in sentences that indicate understanding of both the word’s meaning and correct syntactic usage.
Once words are recognized, students use pragmatic awareness, or sensitivity to how words are used to communicate, to understand the purposes of their use [9]. All of these processes together constitute students’ vocabulary knowledge. Word identification or recognition without comprehension of the meaning and use of a word reveals a deficiency in vocabulary knowledge.
What skills do good readers have?
Good readers know a wide range of oral and print vocabulary. Typically, vocabulary knowledge results from extensive and repeated exposures to words through reading and speaking. One study estimated that good readers read approximately one million words per year [10]. Good readers have superior vocabulary knowledge and possess the following characteristics.
Good readers have strong oral/aural vocabulary
A reader’s oral vocabulary is the collection of words used in speaking [11]. Skilled readers are able to use grade-level words fluently and clearly in their speech and understand those words when used by others in their speech. Oral/aural vocabulary ability transfers to reading once the written word has been deciphered. A skilled reader can recognize that word again with little effort [12]. To do this, readers must develop their decoding skills to the point that decoding occurs effortlessly.
Good readers have strong print vocabulary
Skilled readers are able to read words in written text at or above their grade level and use these words in written communication [13]. When good readers encounter unfamiliar words, many translate this text into speech, either by decoding or getting help from someone else. Once the word is verbalized, good readers automatically recognize the word or engage in a self-regulated process to discover its meaning. This may include but is not limited to analyzing the word’s morphology (roots and affixes) and syntax (part of speech), searching for context clues, or looking up the word in the dictionary [14].
What challenges do adolescent readers face with vocabulary?
Because word identification is one of the foundational processes of reading, middle and high school students with poor or impaired word identification skills face serious challenges in their academic work. Some struggling adolescent readers have difficulty decoding and recognizing multi-syllabic words. For example, words such as “accomplishment” leave many struggling readers unsure about pronunciation or meaning. This is often the case not just because their vocabulary is limited, but also because they are unaware of or not proficient in word-learning strategies based on understanding the meanings and functions of affixes (e.g., prefixes and suffixes) and other word parts [15]. In content areas in which text is more technical and abstract, insufficient vocabulary knowledge can become especially problematic for struggling readers. A major goal of vocabulary instruction is to facilitate students’ ability to comprehend text [16].
In addition, the meanings of many words vary from context to context and from subject to subject, making academic vocabulary especially difficult to acquire. For example, the word meter has distinct definitions in different content areas. In literature, a meter is a poetic rhythm and in math, it is a unit of measurement. In science, a meter is a device for measuring flow. Students may experience difficulty if they do not understand that words have multiple meanings [17].
How can instruction help adolescent students with vocabulary?
Research findings suggest that there is not a single best way to teach vocabulary [18]; rather, using a variety of techniques that include repeated exposures to unknown word meanings produces the best results. Traditionally, independent word-learning strategies, such as the use of dictionaries and context clues, have been common strategies for teaching new vocabulary. Dictionary usage involves multiple skills, such as using guidewords, decoding, and discerning correct definitions [19]. Using context clues involves integrating different types of information from text to figure out unknown vocabulary. These strategies are helpful after multiple encounters with a word but should be used in combination with other instructional practices [20].
The following vocabulary development strategies have been found to be effective in improving adolescent literacy levels.
Pre-teach difficult vocabulary
Pre-teaching vocabulary facilitates the reading of new text by giving students the meanings of the words before they encounter them. This practice reduces the number of unfamiliar words encountered and facilitates greater vocabulary acquisition and comprehension [21]. Leaving students on their own to grasp the content material as well as to decode possibly unfamiliar vocabulary is setting them up for failure. Teachers can introduce both the more unfamiliar specialized academic words that will be used in the lesson as well as non-specialized academic words used when talking about the content.
When considering which non-specialized academic words to emphasize, teachers should consider the structure or structures used in the text. Text structures organize ideas and information according to certain patterns. For example, cause and effect patterns show the relationship between results and the events, people, or ideas that cause the results to occur. Common text structures include cause/effect, problem/solution, comparison/contrast, chronological order or sequence, concept idea with examples, proposition with support, analysis and evaluation of perspectives, arguments, and interpretations. Once the text structure or structures have been determined, teachers can identify non-specialized academic vocabulary words that help students talk about the content within a cause/effect text structure [22]. Examples of non-specialized academic words that are commonly used when talking about cause/effect texts include recognize, analyze, result, impact, and relationship.
Teachers can use the following guidelines when selecting vocabulary to pre-teach:
- Importance of the word for understanding the text;
- Students’ prior knowledge of the word and the concept to which it relates;
- The existence of multiple meanings of the word (e.g., meter in poetry, mathematics, and science);
- Opportunities for grouping words together to enhance understanding a concept [23].
Once vocabulary words have been selected, teachers should consider how to make repeated exposures to the word or concept productive and enjoyable. For example, when introducing a particular word, pronounce it slowly to draw attention to each syllable, provide the word’s meaning, examine word parts (e.g., prefix, root, suffix), write the word on the board, use it in a sentence, and ask a question using the word.
After introducing all words, have students work in pairs or small teams to create groups of related words and to label these groups. Students can then take turns explaining to the class their reasons for grouping words in a particular manner. Students can also work in pairs to check each other’s understanding of the new words [24]. Such activities provide multiple exposures to new words and can be structured in ways that are engaging and enjoyable for students.
Use direct, explicit, and systematic instruction to teach difficult vocabulary
Scientific research supports the use of direct, explicit, and systematic instruction for teaching vocabulary [25]. Vocabulary lessons should be fast-paced, brief, multi-sensory, and interactive (i.e., allow students to see and write new words as well as to hear and speak these words) [26].
Explicit instruction of vocabulary involves the following steps:
- Explain word meanings and model usage of difficult content-area vocabulary in sentences that are relevant to the subject matter concepts that students are currently learning.
- Guide students to practice using the vocabulary in different sentences and contexts and provide corrective feedback.
- Provide time for independent practice with the vocabulary — peer tutoring, reciprocal teaching, and collaborative learning.
- Repeat these instructional steps until students are able to use the new vocabulary independently in their reading and writing [27].
Use students’ prior knowledge and provide opportunities for multiple exposures to new words
To learn and retain new words and concepts, students need to connect these words and concepts to what they already know. They also need repeated exposure to the words and concepts plus opportunities to practice using them in different contexts. Teachers can facilitate struggling readers’ learning and retention of new vocabulary in the following ways:
- Prior to pre-teaching vocabulary, elicit students’ prior knowledge of the content in which the new vocabulary is used and then relate their prior knowledge to the new vocabulary. It is also helpful to make a word map on the board, chart paper, or overhead to show the connections between students’ prior knowledge and the new vocabulary [28].
- Provide multiple repetitions of the words in different contexts [29]. For example, within the context of explaining new concepts, giving directions, or summarizing ideas, use the new words repeatedly. You may also want to pronounce these words more slowly and pause after saying them to allow students time to identify and focus on the words.
- Point out that in academic settings certain non-specialized academic words are used when talking about content. Point out and model usage of these words and phrases. For example, when reading about or discussing the causes of the civil war, point out and model usage of such words as cause, consequence, relationship, etc. Guide students to use these words in their speech and writing.
- Provide students several opportunities to apply new word meanings across different situations [30]. For example, place students in small groups to discuss their understandings of the new words. Have them develop their own word maps to show relationships among the new words and connections to the important concepts. A word map is a diagram used to help show the relationships of various topics or concepts to a chosen word or phrase. Have them write sentences using the new words in different ways, then share these orally with the class.
Even more repetition and time with new vocabulary should be allowed for students with learning disabilities. English language learners also require more exposure and practice with English vocabulary [31].
Use computer technology to help teach new vocabulary
Vocabulary instruction using computer technology can be particularly helpful to struggling readers who need additional practice with vocabulary skills [32]. Computer technology allows for engaging formats, such as interfaces modeled on computer games. Hyperlinks that allow students to click on words and icons can add depth to word learning. Students may find online dictionaries more useful and accessible than print dictionaries. Computers also provide access to content-area-related websites hosted by such institutions as museums and libraries. Finally, computer program animation may hold students’ attention longer than plain text [33].
What do we still need to know?
Research has yet to demonstrate the most effective types of professional development needed for teachers to become proficient in vocabulary instruction. Fully equipping the teachers to address adequately the issue of vocabulary in classrooms is an important step toward improving the vocabulary of adolescents. Another gap in the knowledge base is improved understanding of how vocabulary instruction should be integrated with comprehension instruction. We know that repetition and prior knowledge help familiarize adolescents with new vocabulary, but we need to determine what instructional techniques can help educators ensure that adolescents grasp the contextual meanings of vocabulary [34].