The process of learning new vocabulary is an essential component to learning language skills (Sénéchal, LeFevre, Hudson, & Lawson, 1996). Rapid learning including language and vocabulary development begins in early childhood (Tamis-LeMonda, & Rodriguez, 2008). The ability to acquire vocabulary, and the skills to read and write is an ongoing process that continues to develop throughout a lifetime, however the most important and crucial time for literacy development is the early years from infancy to the age of 8 (NAEYC, 1998). Children have remarkable skills to acquire new word meanings (Carey & Bartlett, 1978); word learning rates of approximately eight to ten words each day (Beck & McKeown, 1991; Nagy & Herman, 1987). Language acquisition and literacy skills co-exist; having the ability to enhance language development through activities that are literacy-related during the critical early preschool years (Carey, 1985; Snow, 1991; Snow, Burns, & Griffin, 1989). Well-developed vocabulary skills play a significant role in future reading achievement and children's ability to communicate effectively. By the age of 3, it is typical for children to form simple sentences, use appropriate grammar, and experience a growing vocabulary, by the age 6, most children learn to comprehend 10,000 words (Thompson, 2004).
Vocabulary acquisition has been shown to contribute to reading comprehension and literacy growth (Stahl & Fairbanks, 1986). Through interactions, and language exposure, new vocabulary can be learned based on current word and concept knowledge (Adams, 1990; Anderson & Freebody, 1981; Baumann & Kame`enui, 1991). Repeated exposure to language rich interactions allows for practice and expansion of receptive and expressive vocabulary as well as comprehension. Delays in early vocabulary skills have been reported as an "at risk" indicator for later reading difficulty (Scarborough, 1998). Young children exposed to enriching language experiences develop a solid foundation for vocabulary development. Contributing to vocabulary development and comprehension is repeated encounters with words in meaningful contexts (Hart & Risley, 1995). Children who struggle to read and acquire vocabulary continue to show deficits and life long difficulties, while children, who are successful with early reading skills, continue later reading success. This is known as the Matthew Effect (Stanovich, 1986). Essentially poor readers remain poor readers and good readers become even better readers.
Typical Vocabulary Development
At an early age, children have the ability to successfully understand and use language and vocabulary. Before the age of 2 years, children seem to learn new words more easily from social interaction and direct references than from indirect sources (Robbins & Ehri, 1994). During the preschool years, young children learn new words relatively quick and easily. Young children are capable of learning approximately 3,000 new words per year and potential to acquire a consistent vocabulary of 8,000 to 14,000 words by the age of 6 years old (Beck & McKeown, 1991).
Justice, Meier, and Walpole (2005) reported three strategies for vocabulary development and acquisition include (a) incidental exposure (b) gradual learning and (c) direct teaching. Incidental exposure refers to informal experience with words during daily activities (Nagy & Herman, 1987) through interactions between adults and children. Gradual learning entails the development process moving "from immature or incomplete word representations to mature accurate representations" (Justice et al., 2005, p.18). The third strategy for vocabulary development, direct teaching, entails vocabulary acquisition involving explicit instruction through synonym drill, classifying, word meanings (Stahl & Fairbanks, 1986), and direct explanations (Robbins & Ehnri, 1994).
Graves (1987) reported 70% of vocabulary acquisition is a result of direct vocabulary instruction, and by the time children reach sixth grade, 80% of vocabulary knowledge is learned through direct instruction (Biemiller, 2001). Direct vocabulary instruction is the acquisition of "word meanings through direct explanations from parents, educators, and peers, and within texts" (Pythian-Sence, & Wagner, 2007, p. 6). Vocabulary can be acquired through direct instruction, however research also supports the idea that children have the ability to process and learn independently through incidental learning (Huckin & Coady, 1999; Jenkins & Dixon, 1983; Krashen, 1993; Nagy & Herman, 1997). Incidental learning provides an opportunity to gain knowledge for vocabulary acquisition at a very young age through exposure to books and reading. According to Nagy and Herman (1984), only 200 to 300 words per year are learned as a result of direct instruction of vocabulary. Which would suggest direct instruction is only minimally responsible for vocabulary acquisition. Reading, daily activities, television (Nagy, Anderson & Herman, 1984), adult-child storybook reading, environment and conversations with others (Roth, 2002) encourage incidental learning opportunities.
While research has shown children can learn new vocabulary through incidental exposure, children who have delayed vocabulary skills are not as successful as their normally developing peers. Children who are considered "at risk" for language and reading difficulties struggle to learn new vocabulary words through incidental learning activities (Robbins & Ehri, 1994; Sénéchal, Thomas & Monker, 1995) and require more explicit vocabulary instruction with multiple exposures (Robbins & Ehri, 1994). After a single exposure to an unfamiliar word, typically developing children have the ability to form a rough mental representation when various types of information are provided (Carey & Bartlett, 1978; Templin, 1957). In addition, young children with normal language development can recognize and produce novel words following incidentally hearing a word produced with limited exposure (Carey & Bartlett, 1978; Heibeck & Markman, 1987). Planning and structuring children's vocabulary learning towards an incidental and independent capacity building on prior knowledge has been described as scaffolding (Ninio & Brunner, 1978; Olson & Platt, 2000). Without any direct or specific instruction, just engaging with others during conversations appears to scaffold the acquisition of novel words and language proficiency (Elley, 1989; Penno, Wilkinson & Moore, 2002; Rice et al., 1992; Sénéchal, 1997).
Vocabulary acquisition is a gradual process allowing for novel word learning in which words develop over time and repeated exposure to form new and accurate representations (Justice, et al., 2005). Carey and Bartlett (1978) describe this word learning skill as the process of fast mapping. Fast mapping begins the process of word learning, which an initial representation and word meaning is created based on a single exposure (Carey & Bartlett, 1978) without specific instruction (Crais, 1992). A slow mapping process, which word learning and accurate labels develop over a period of time with multiple exposures to novel vocabulary follows (Curtis 1987). Repeated exposures to novel vocabulary assists in the acquisition of receptive vocabulary, however Waring and Takaki (2003) found only a 10 to 15% chance of acquiring new vocabulary during reading activities even after 18 or more exposures and may depend on reading proficiency (Zahar, Cobb & Spada 2001). Children with a larger vocabulary have the ability to acquire more words and require less exposure than do children with a lower vocabulary set (Robbins & Ehri, 1994).
When learning new vocabulary words, possible meanings and referents are endless. When children do not have a label for an unfamiliar object, strategies are used to naturally assign a new meaning (Carey & Bartlett, 1978; Markman & Wachtel, 1988). The principal of mutual exclusivity (ME) has been studied as a strategy used when a name has not already been assigned to apply meaning and labels to unfamiliar objects (Markman, 1989). The ME effect is a term used to describe the reluctance to accept an additional label for an object already named in one's repertoire based on the assumption that only one label is assigned to each object (Markman, 1991, 1994; Markman & Wachtel, 1988; Markman, Wasow & Hansen, 2003; Merriman & Bowman, 1989). When learning new vocabulary, initially children have the expectation that words belong to specific categories and are mutually exclusive to that category (Markman, 1989). Assumptions are made and children begin to organize and group objects together into categories based on similar characteristics. Markman (1989) reported children use category assumptions as a strategy to process information and extend their knowledge. By categorizing new vocabulary, children identify common characteristics and have the ability to discriminate between attributes, which leads to grouping properties into different subcategories (Carey, 1985; Waxman, 1988).
Markman and Wachtel (1988) examined preschool children's word learning and the mutual exclusivity principle. Participants were presented several random pairs of objects. One item in each pair was familiar, such as a banana. The second object in each pair was an unfamiliar object, such as a pair of tongs. Children were asked "show me x" in which x represented a nonsense syllable for each set of familiar and unfamiliar objects. Results indicated children were more likely to interpret x as the unfamiliar object (i.e., the tongs) than familiar object (i.e., the banana). Markman and Wachtel (1988) hypothesized these findings suggested that when an unfamiliar word is heard while being presented with a familiar and unfamiliar object, children will use ME to rule out the already known object as the referent for the nonsense syllable. Therefore, based on ME principle, x was assumed to refer to tongs, the unknown object.
Jaswal and Hansen (2006) examined twenty-four preschool children ages 3 and 4 and the effects of ME on vocabulary learning. Six object pairs were presented. Each pair consisted of one novel word object and one familiar object. Children were requested to look at the objects, and a comment was made "look at these, isn't it interesting?" and then requested to "give me the blicket" when presented a familiar object (i.e., crayon) and a novel object (i.e., pencil holder). Results revealed that children in this study assumed the novel label referred to the unfamiliar object because young children do not believe objects could be a member of both the blicket category and the crayon category. Therefore assumptions regarding ME principle in which one label represents one object may be an effective and successful strategy for organizing and word learning indirectly (Markman & Wachtel 1988; Woodward & Markman, 1998).
When children apply a second label for an already known object, Markman (1991) suggests children use ME as a strategy to organize the environment and process new information. Studies of preschoolers and ME (Halberda, 2003; Markman, 1989, 1990; Markman, et al., 2003; Merriman & Bowman, 1989; Merriman, Marazita, & Jarvish, 1995) support that young children have to ability to assume a novel label refers to an unfamiliar referent when presented with both known and unknown objects. Due to ME and the assumption which suggests each object has one label and one category, children automatically select the unfamiliar object by default (Markman & Wachtel, 1988; Markman, et al., 2003). When a novel label is heard, the theory of ME discourages children to accept and apply a novel (second) label to an already named object. Instead, through process of elimination, children attach the new word meaning to the unknown object. For example, when presented with a ball and an unknown object and asked, "Give me the corb," the child assumes a "corb" is the unknown object because the ball already has a name (i.e., a ball). According to ME, the ball cannot have another name because the object (ball) is mutually exclusive to the already known word (ball) (Halberda, 2003; Markman, 1990).
Principles of ME suggest that words do not have multiple referents; each referent has one label, which is exclusive to that object. Clark (2003) argued words are not always mutually exclusive to one label. Words such as synonyms (i.e., rabbit and bunny, or ship and boat) have overlapping referents or words that incidentally overlap can also occur (i.e., if a neighbor happens to be a doctor, the words "neighbor" and "doctor" overlap to identify the same individual). Learning a second label to an already known word appears to be an easier task for older children as a result of having more opportunities and life experiences allowing them to have more success than very young children. As children reach approximately 2 years of age, the ease of learning new words, forming meanings and learning second labels (i.e., synonyms) begins to change (Regier, 2005).
Liittschwager and Markman (1994) had intentions to corroborate previous research suggesting that 2-year olds were less successful at learning a second label (synonym) for an already learned word. Participants included 16 and 24 month old children who were introduced with a novel label (synonym) for either a familiar or an unknown object. Participants were asked to show each object a puppet asked for (items including the known object, novel object that was presented previously as well as a third no-label object not yet presented to the participants). Results confirmed 16-month-olds had the ability to learn new words for unknown named object however struggle to learn a second label (i.e., synonym) for words already in their repertoire. However, found 24-month-olds were able to accept a second name (synonym) for an already known word and override the ME bias. This finding indicated that participants successfully suppressed the principle of ME and did not exhibit significant resistance to synonym learning for an already named object.
Similar studies (Haryu & Imai, 1999; Mervis, Golinkiff, & Bertrnad, 1994; Taylor & Gelman, 1989) support the ability of young children to accept a second label for an already known object, overriding the ME principle. Taylor and Gelman (1989) found children as young as 24 months are able to accept multiple labels and successfully identify target synonyms. Participants were instructed that a fep was a sedan type car. When presented with a sports car and a sedan, the participants referred to the sedan and not the sports car when asked to "show the fep". However, when participants were presented with both car types and asked to show the examiner the "cars," participants showed both sports car and sedan establishing a second label (synonym) to identify target word successfully. Young children accept multiple labels for objects and suppress ME (Haryu & Imai, 1999) by establishing subordinate categories (similarities and differences between words and/or categories). For example, a cat and an animal can refer to the same thing due to the ability for a cat to assume the category cat and also assume the subordinate category of animal (Liu, Michnick, Golinkoff & Sak, 2001). Children have to override ME in order to learn a second label. Children learn a second label by first assuming the unfamiliar word is attached to an unfamiliar object, however enhanced with elaborated commenting and pointing, children have the ability to accept a synonym and suppress ME the principle (Haryu & Imai, 1999).
Not all children demonstrating academic or language difficulties present with severe delays that qualify them for services under traditional district or state guidelines. Often children may present with mild-moderate delays with standardized test scores too high to be eligible for direct speech and language services; however, general delays present in the areas of speech and/or language may be predictors of future reading difficulties (Catts, Fey, Zhang & Tomblin, 2001). Children whose scores are low but not severe enough to qualify for services, are considered at risk for not being identified until later academic concerns arise. Research has shown that children who have a history of language learning difficulties; oral language, phonemic awareness, print knowledge (Lonigan, 2006) memory and weak verbal abilities (Wise & Snyder, 2003), often struggle with later reading development (Catts, et al., 1999; Scarborough, 1990).
Several studies regarding early intervention and young children who are at risk for future reading delays characterize a child with reading difficulties as one who performs greater than 1 SD below the mean on a reading comprehension assessment (Catts, et al., 2001; Catts, Hogan & Fey, 2003; Torgesen, Wagner, Rashotte, Rose, Lindamood, Conway & Garvin, 1999). Based on findings from several language assessments it is typical for test authors and publishers to consider scores between 85 and 115 (within 1.0 SD) within normal limits. Eligibility ranges for school criteria vary from state to state. Typical ranges often used to determine disorder eligibility in schools, range from 1.5 to 2.0 standard deviations. Eligibility criterion for the district included in this study is 2.0 SD from the mean. Catts, et al. (2001) suggests specific language impairment (SLI) is a disability category used for children who perform below normal (i.e., standard scores <85) language abilities on one or more language tests.
Typically children do not qualify for direct speech and language services if delay is not greater than -1.5 SD indicating they may need monitoring, increased exposure to language, extra time to develop, etc. Children scoring greater than -1.5 SD are referred to as having a specific language impairment (SLI) (Catts, et al., 1999) and may qualify for services. Children experiencing difficulty with language, phonemic awareness and vocabulary when entering pre-school and kindergarten could be at risk for future reading difficulties (Snow, et al., 1998) if early intervention does not take place. For purposes of this study, scores within 1.0-1.4 SD were considered low average, or "at risk," and 1.5 SD was indicative of a language impairment. This study was interested in the word learning skills and abilities of those students who were considered at risk. Children who are considered at risk imply direct service interventions, which may have benefited them and could potentially prevent later reading disabilities were not provided.
Reading inevitably becomes essential for learning. Shared storybook reading to very young children prior to print knowledge can foster language acquisition (Sénéchal, LeFevre, Thomas & Daley, 1998; Whitehurst, 1996; Whitehurst & Lonigan, 2001). As children begin learning to read the development of language skills, vocabulary, phonemic awareness (Bowey, 1994; Dickinson, McCabe, Anastasopoulos, Peisner-Feinberg & Poe, 2003; Hart & Risley, 1995;) and print knowledge (Whitehurst & Lonigan, 2002; Bowey & Patel, 1988) play an important role in the development of literacy. Given the close relationship between literacy and language skills, ultimately young children exhibiting deficiencies in any of these areas, are at-risk for developing later reading difficulties (Cavanaugh, Kim, Wanzek & Vaughn, 2004; Snow, et al., 1998).
Research has found that children come differently prepared and (Wagner, Torgesen & Rashotte, 1994) begin school with varying levels of "readiness" including print knowledge, picture naming (Fielding, Kerr & Rosier, 2007; Snow, et al., 1998), language, communication, and skills pertaining to academics (letter recognition, colors, shapes, etc). Children who enter preschool and kindergarten with limited proficiency regarding early literacy skills are at a disadvantage and at risk for reading failure (Bailet, Repper, Piasta & Murphy, 2009). Once a child struggles and falls behind with developing reading skills, it is often very difficult to "catch up" and reach the level of their peers and will continue to have difficulties (Allington & McGill-Franzen, 1989; Good, Simmons & Smith, 1998). However, given ideal circumstances and with early intervention, young language learners have the ability to develop vocabulary and language essential for basic reading skills (Carnine, Silbert & Kame`enui, 1990).
Vocabulary acquisition is critical to academic development and having a rich knowledge of vocabulary is central to learning language (Baker, Simmons, & Kame'enui, 1998). When acquiring new vocabulary, children have the ability to build on prior knowledge to access word meanings and connect basic concepts to learn new information and expand word knowledge which can lead to academic success (Armbruster, Lehr & Osborn, 2001).
Many young children have the ability to build and develop the skills necessary to learn language and literacy skills on their own successfully without the aid of early intervention. However not all children are able to do so independently and struggle to keep up a similar the pace to that of their peers and "lag" behind. Stanovich (1986) characterizes this discrepancy in achievement as the "Matthew effect." When children first begin to read, the discrepancy is considerably small, almost unnoticeable. As good readers become competent readers and poor readers continue to lack growth in literacy skills, this gap eventually widens to noticeably separate the successful readers from the struggling reader. Once again making it nearly impossible and very difficult to close the gap and "catch up" to peers, remaining "at risk" and below grade level without some form of intervention (Allington & McGill-Franzen, 1989; Good, et al., 1998).
Justice, et al. (2005) examined vocabulary acquisition of at-risk kindergarten children struggling with literacy and vocabulary development, specifically effects of prior vocabulary knowledge and elaboration of novel words on word learning. The evaluation design was a comparison group study using a pretest-posttest design to randomly assign 57 kindergartners to a treatment or comparison group. All children were pre-tested to determine knowledge of target vocabulary from 10 storybooks which were read in 20 small group reading sessions to children in the treatment group. Novel words were embedded in the stories and randomly presented either with or without elaboration. The comparison group was presented novel words without elaboration as the words naturally occurred in the text of the storybook. After a 10-week reading period, post-tests were administered and intervention was completed using the same strategies as the original treatment group. As a whole, gains in vocabulary were considerably higher for participants in treatment groups exposed to elaborated words versus comparison group participants. Results suggested exposing vocabulary during repeated storybook readings is a viable strategy used to facilitate word learning, and elaborated commenting of target words in context of the story can increase vocabulary development (Justice, et al., 2005).
Joint Book Reading
One context that supports the strategies children use for vocabulary development is joint book reading (JBR) (Ewers & Brownson, 1999; Hargrave & Sénéchal, 2000). JBR involves the interaction between adults and children reading stories together with the adult using specific strategies to engage the child and scaffold language interactions for developing children's vocabulary skills and knowledge (Ard & Beverly, 2004; Crowe, 2000; Justice & Ezell, 2000; Sénéchal, 1990; Whitehurst & Lonigan, 1998). Children who struggle with language learning and present with inadequate vocabulary skills can benefit from JBR and increase literacy skills (Bridge, 1979; Norris, 1988). Repeated readings during JBR of the same story provide multiple exposures to new words and facilitate the development of vocabulary (Carey, 1978; Justice et al., 2003; Sénéchal, 1997) and children begin to correlate familiar to unfamiliar context (Snow & Goldfield, 1983).
Reading books to very young children can foster an understanding of phonemic awareness and promote successful development of language skills, and literacy (Bus, Ijzendoorn van & Pellegrini, 1995). Literature suggests early JBR positively impacts language skills (Elley, 1989; Sénéchal & Cornell, 1993), provides linguistic advantages (Moerk, 1985) and promotes cognitive and intellectual development (Bus, et al., 1995) for infants and toddlers. JBR creates a languageâ€‘enriched environment that encourages vocabulary development (Elley, 1989; Jenkins & Dixon, 1983) and is fundamental for emergent literacy and building skills for reading success (Bus, et al., 1995; Richman & Colombo, 2007).
During JBR, adults have the opportunity to provide children their undivided attention (Sénéchal et al., 1996) while reading. Not only do adults read, but interact and allow young children to react while enhancing the context of a reading activity beyond independent reading alone (Elley, 1989; Sénéchal et al., 1998; Snow et al., 1998). Children are able to achieve a relationship between oral and written language participating in these share storybook experiences. Adults direct this experience by identifying and commenting on pictures and vocabulary illustrated on the page, ask questions and often relate the story to children's own personal experiences (Kaderavek & Sulzby, 1998). Reading to children is a form of social interaction which creates an environment that facilitates oral language, vocabulary acquisition, intellectual development and linguistic skills essential for literacy (Vygotsky, 1978; Whitehurst & Lonigan, 1998).
Young language learners can benefit from sharing these experiences. Findings by Karras and Braungart-Rieker (2005) stress the important role parents play during JBR activities to contribute to the success of language and literacy learning. Parents provide a rich environment for consistent learning opportunities by engaging in joint attention (Tomasello & Farrar, 1986), using details in their language to encourage learning and provide ample opportunity for vocabulary acquisition. Language skills are reinforced (Murphy, 2007) as adults disguise instruction by guiding learning; identifying pictures by pointing to pictures to match words with objects (Bruner, 1985), commenting, asking questions (Ninio, 1983), interacting, expanding (Murphy, 2007) and responding to children's cues and sharing a general interest. Children use this opportunity to learn new words not typically seen in their environment through illustrations and parent guided learning (Tomasello & Farrar, 1986).
Creativity, entertainment, and the element surprise are used in most children's storybooks to entice and encourage participation and increase arousal levels (Berlyne, 1960). Stories ideally facilitate participation, discussions, and joint interaction between adults and children (Justice & Ezell, 2004) resulting in comprehension and learning from the context of the story (Elley, 1989). Print knowledge, phonemic awareness and literacy skills gained through JBR as young as toddlers and preschoolers, has been thought to be essential for establishing the framework to build upon for successful academic performance (Catts, et al., 2002).
Evidence suggests young children benefit from early intervention and successful reading instruction with regards to literacy (Cavanaugh, et al., 2004; Good, et al., 1998). A number of studies have examined book reading and its effects on early literacy concepts, reading outcomes as well as intervention strategies and delivery methods used for young children to support vocabulary development during the prime years of literacy development. More than 25 of these studies emphasized literacy development specifically targeting kindergartners with language delays as well as children with emerging literacy skills who are considered "at risk" for developing later reading difficulties (Cavanaugh, et al., 2004). There has been little research investigating the use of elaborated commenting within a JBR context for kindergarten students, therefore further clinical research is needed for vocabulary enhancement techniques.
Teaching Strategies for Vocabulary Instruction
Children learn words and gain knowledge and understanding from others in their environment (teachers, parents, peers, etc). Vocabulary knowledge is gained when participating in a variety of explicit learning activities. Direct teaching of word meanings, book reading, learning basic concepts from the world around us and the environment such as listening and experiences with peers, casual conversation, television and movies, etc. are all examples of learning activities (Biemiller, & Slonin, 2001). Vocabulary learning is significantly impacted when specific information is presented regarding word meanings and definitions. A study by Dockrell and Messer (2004) demonstrated children were more likely to acquire word meaning when exposed to explicit semantic information, as opposed to word learning with out this type of support.
Several studies of vocabulary acquisition have investigated JBR focusing specifically on teaching strategies for vocabulary instruction and the impact these strategies have on word learning. Several teaching strategies were used to examine use of questions and commenting (Elley, 1989; Ewers & Brownson, 1999; Ezell & Justice, 1998; Ninio, 1983; Scarborough & Dobrich, 1994; Sénéchal & Cornell, 1993; Snow, 1983), extensions and requesting (Cornell, Sénéchal & Broda, 1988; Ewers & Brownson, 1999), elaborating (Justice, et al, 2005; Snow & Goldfield), repeated exposure (Cornell, et al., 1988; Justice, 2002; Robbins & Ehri 1994), verbal and non-verbal cues (Sénéchal et al., 1995), recasts (Ewers & Brownson, 1999; Pemberton & Watkins, 1987; Sénéchal & Cornell, 1993) etc. and their effects during JBR activities.
Few studies have been conducted to demonstrate word learning strategies and the effects of synonyms on vocabulary acquisition. Elley (1989) examined the use of explanations and word meanings used by parents and teachers while reading to young children. Elementary school children made greater gains when the reader gave additional input such as labeling illustrations paired with pointing, short explanations (i.e., synonyms) of target words during reading compared to children who simply listened to the story. When adults pause during JBR to provide a short explanation and describe illustrations (Penno et al., 2002) vocabulary acquisition skills improve.
Pemberton and Watkins (1987) investigated vocabulary acquisition through recasting synonyms during JBR with young children 3 years of age. Participants were read stories containing synonyms, which were assumed to be part of existing repertoire. Initial presentation of sentences were heard with target vocabulary followed by a sentence embedded with a synonym. The task required children to associate this new label with the familiar concept. Results indicate synonyms can contribute to the ability to compare the meaning of a known word with an unknown word. Essentially children learned a synonym for a word already known or had at minimum general knowledge of. Children can learn to accept a second label for an object already learned. Au and Glusman (1990) found effects of ME are apparent when children perceive two words to be at the same hierarchy level, however have shown the ability to resist ME and learn multiple labels for referents which are believed to be at different hierarchical levels. Littschwager & Markman (1994) argue, ME does not prohibit even very young children from learning more than one label as a rule, but rather a bias in which children have the foresight to disregard ME and learn new vocabulary words.
Ewers and Brownson (1999) investigated word learning strategies comparing the use of what and where questions to recasting synonyms within the body of a story. While children were able to learn new words through recasting, using questions had a larger impact and produced better results with more learned words. JBR strategies, particularly the use of questioning and commenting has been found to have a profound influence on language skills and enhance vocabulary knowledge (Elley, 1989; Ezell & Justice, 1998; Ninio, 1983; Scarborough & Dobrich, 1994; Snow, 1983). Children presented with word elaboration and teacher explanations of target words (Elley, 1989; Penno, et al., 2002) and/or direct explanations of word meanings (Bielmiller & Boote, 2006) made more improvement in vocabualry knowledge than those without explanations. Questioning and commenting is a strategy naturally used to provide additional information about a story. Children are able to use prior knowledge and personal experiences to help make connections to better understand new vocabulary and apply information for story comprehension (Newkirk & McLure, 1992). Questions can be strategically used to encourage participation in ongoing communication and turn-taking resulting in more knowledge and comprehension (Drabble, 2006). Commenting and elaboration give children the opportunity to modify their thoughts and ideas and make them unique to their interpretation. When asking and answering questions, children are typically expected to give a specific response. Specific information may not be required to respond to comments and elaboration as it is with questioning (Ard, 2004).
Allowing children to be active participants (use of questions, commenting, pointing labeling, etc) during JBR has been used to develop language in young children (Sénéchal, Thomas and Monker, 1995). Asking questions, using extensions and requesting clarification during JBR can also produce a significant increase in children's vocabulary and encourages further discussion (Cornell, et al., 1988; Ewers & Brownson, 1999). These strategies specifically asking questions provides a vehicle in which adults can manipulate the environment to elicit conversational turn-taking behaviors, joint attention, and elicit responses to encourage elaboration of story details (Ezell & Justice, 1998).
Repeated exposure and the frequency with which adults produce new words reinforces vocabulary and increases comprehension and language development (McGee, & Schickedanz, 2007). There is no absolute number of exposures or conditions necessary for word learning, studies have established word learning is possible with as few as one to four exposures (Elley, 1989; Ewers and Brownson, 1999; Sénéchal, 1997; Sénéchal & Cornell, 1993) to new words. Cornell, et al. (1998) found young language learners who were encouraged to participate in exchanges of questions and answers and exposed to target vocabulary multiple times during JBR resulted in gains in novel vocabulary development. Studies have shown children are able to learn receptive vocabulary when books were reread more than one time (Elley, 1989; Robbins & Ehri; Sénéchal & Cornell, 1993). Supporting these finding, research by Justice et al. (2003) and Sénéchal (1997) found children were able to acquire improved receptive and expressive vocabulary skills when repeated exposures to target words was used. When presented with multiple exposures to unfamiliar words, children have the ability to reorganize and "map" information already known and gather new information to determine word meanings and rapid word learning (Crais, 1992). Repeated exposure allows representation of many new words to evolve simultaneously (Ard, 2004). Repetition of new words carrying associated meanings and verbal cues is useful for vocabulary acquisition for young language learners.
Nonverbal cues can also help children gain significant knowledge regarding vocabulary and their meanings during JBR. During communication and shared storybook reading, attention is repeatedly guided to information regarding target word using nonverbal cues (McNeil, 1992; Tomasello & Akhtar, 1995). Use of nonverbal cues when introducing novel words to children like pointing to illustrations, manipulation of objects and gestures, etc. creates a scaffolding effect where the child is led to believe the word which is spoken is referring to the referent being manipulated or pointed to (Tomasello & Akhtar, 1995).
JBR experiences specifically the interaction between adult s and children play a crucial role in the development of emergent literacy. Shared reading experiences have positive effects on children's developing language skills, and are a great predictor for reading success. Many word learning strategies have been investigated and used regularly as tools adults' use for vocabulary instruction. At this time no single method is considered superior (Simmons & Kameenui, 1990), however there is significant evidence to support language and vocabulary learning from each of the aforementioned word learning strategies. Word learning strategies encourage students to engage critical thinking skills for gaining word knowledge and support development of a mature and functional vocabulary repertoire (Mezynski, 1983; Stahl & Fairbanks, 1986). Vocabulary growth is developed through shared book reading experiences between adults and young language learners. Research has shown that young children who enter school with language delays are at a higher risk for developing later reading and academic difficulties (Catts, 1993; Scarborough & Dobrich, 1994). While current research supports the use of JBR as an intervention strategy for young children with delays in language (Ratner, Parkner & Gartner, 1993), there is a need for further research regarding those children who do not have a language delay but are considered at risk for developing later academic difficulty.
This study examined vocabulary acquisition for at risk kindergartners facilitated by elaborated commenting during joint book reading.
Do at risk kindergarten students demonstrate greater receptive vocabulary acquisition than expressive vocabulary acquisition given joint book reading experiences enhanced with elaborated commenting compared to joint book reading alone?
Do at risk kindergarten students acquire more vocabulary words receptively from joint book reading experiences enhanced with elaborated commenting compared to joint book reading alone?
Do at risk kindergarten students acquire more vocabulary words expressively from joint book reading experiences enhanced with elaborated commenting compared to joint book reading alone?