The role of vocabulary versus knowledge in children’s language learning: a fifty-year perspective

I argue in this paper that conceptualizing the gap in quantity of words, which is useful in emphasizing the size of the challenge, misconceptualizes the real differences, which are in kn

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Infancia y Aprendizaje

Journal for the Study of Education and Development

ISSN: 0210-3702 (Print) 1578-4126 (Online) Journal homepage: https://www.tandfonline.com/loi/riya20

The role of vocabulary versus knowledge

in children’s language learning: a fifty-year

perspective / El papel del vocabulario frente al conocimiento en el aprendizaje lingüístico de los niños: una perspectiva de cincuenta años

Catherine E Snow

To cite this article: Catherine E Snow (2017) The role of vocabulary versus knowledge

in children’s language learning: a fifty-year perspective / El papel del vocabulario frente al conocimiento en el aprendizaje lingüístico de los niños: una perspectiva de cincuenta años, Infancia y Aprendizaje, 40:1, 1-18, DOI: 10.1080/02103702.2016.1263449

To link to this article: https://doi.org/10.1080/02103702.2016.1263449

Published online: 12 Jan 2017. Submit your article to this journal

View Crossmark data Citing articles: 2 View citing articles

The role of vocabulary versus knowledge in children’s language learning: a fifty-year perspective / El papel del vocabulario frente

al conocimiento en el aprendizaje lingüístico de los niños: una

perspectiva de cincuenta años

Catherine E Snow

Harvard Graduate School of Education (Received 26 April 2016; accepted 6 July 2016) Abstract: Much public attention has been drawn to the ‘30 million-word gap’ between children growing up in more vs less privileged families I argue in this paper that conceptualizing the gap in quantity of words, which is useful in emphasizing the size of the challenge, misconceptualizes the real differences, which are in knowledge of the world rather than just vocabulary size, and risks luring early childhood educators and parents into overly simple solu-tions If we recognize the challenge as one of knowledge rather than just vocabulary size, we also are in a better position to support second language learners whose knowledge base across both languages is a better predictor of academic success than vocabulary in the second language.

Keywords: social class differences; vocabulary; knowledge; early childhood education; interventions

Resumen: La ‘brecha de los 30 millones de palabras’ entre niños que viven

en familias más y menos privilegiadas ha acaparado mucha atención pública.

En el presente trabajo argumento que conceptualizar la brecha entre estos niños en términos de cantidad de palabras, aunque sea útil para enfatizar la magnitud del desafío, conceptualiza de forma inadecuada las diferencias reales, que radican más en el conocimiento del mundo que en el tamaño de vocabulario, y presenta el riesgo de tentar a padres y educadores de la primera infancia a buscar soluciones excesivamente simplistas Si reconocemos este desafío como uno de conocimiento más que uno de tamaño de vocabulario estaremos en mejor posición para ayudar a los niños que están aprendiendo una segunda lengua, y cuya base de conocimiento común a ambas lenguas es

un mejor predictor del éxito académico que el vocabulario en la segunda lengua.

Palabras clave: diferencias de clase social; vocabulario; conocimiento; educación en la primera infancia; intervenciones

English version: pp 1–8 / Versión en español: pp 9–16

References / Referencias: pp 17–18

Translated from English / Traducción del inglés: Miguel del Río

Author’s Address / Correspondencia con la autora: Harvard Graduate School of Education, 14 Appian Way, Cambridge, MA 02138, USA E-mail:

Catherine_Snow@gse.harvard.edu

Vol 40, No 1, 1–18, http://dx.doi.org/10.1080/02103702.2016.1263449

Early childhood educators and policy advocates have recently exploited the meme ‘30 million-word gap’ to direct attention to social class differences in children’s vocabularies (e.g., Suskind, 2015) The 30 million words separating more privileged children from those growing up in poverty and in low-literacy homes do not, of course, refer to their own vocabularies, but rather to the number of words they have had a chance to hear by the age of three A study conducted in the 1980s by Betty Hart and Todd Risley, published in the book Meaningful Differences in the Everyday Experience of Young American Children (1995), displayed the multiple levels on which children growing up in less-privileged circumstances miss out on opportunities to hear language: their parents on average spend less time playing with and talking to them; when they are with their children, the low-income parents typically talk less, produ-cing fewer and shorter utterances; and they are less responsive to their children’s communicative attempts In addition, middle-class parents are much less likely

to tell their children to shut up or to deny their requests without explanation than are low-income parents, and more likely to provide praise and words of encour-agement Calculating the differences observed in regular hour-long recordings over two-plus years, and extrapolating to age five, it is possible to estimate that children in the least linguistically enriched households do, indeed, hear

30 million fewer words than the children of more highly educated, professional parents

The Hart and Risley findings were published in 1995, but it took almost

20 years for them to have a strong and visible influence on public perceptions, early childhood practices or policy By 2016, the findings have been cited over 5,000 times, and have provided a headline for an array of social policy initiatives

In this paper, I put the Hart and Risley findings in historical context, by briefly reviewing the history of thinking about vocabulary development in my own research and that of others in the field, before scrutinizing the degree to which the current focus on vocabulary in education for young children is well founded Given the influence that focus is having on the utilization of funds, design of programmes and shaping of policy, it is desirable to consider the range of benefits

it can generate and the limits on those benefits

Vocabulary neglect

The renewal of interest in language acquisition sparked by Chomsky’s theorizing and taken up enthusiastically by Roger Brown (1973), Martin Braine (1971) and others in the 1960s and 1970s largely ignored the specific words children pro-duced, in favour of focusing on the grammatical structures (e.g., pivot-open) and semantic relationships (e.g., possession, location, actor-action) expressed in their early utterances Some level of interest in vocabulary emerged with the observa-tion that a threshold number of words known (50–150) typically preceded the first multi-word utterance (Brown, 1973), and then with the observation that children show a sudden rapid increase in speed of word learning — the vocabulary spurt — around that threshold (e.g., Bloom,1973; Nelson,1973) The vocabulary

spurt was described as a rapid accumulation of nouns in the earliest relevant findings (e.g., Goldin-Meadow, Seligman, & Gelman,1976) Subsequently it was noted that (a) not all children show a period of sudden rapid growth (Ganger & Brent, 2004), and (b) that the overrepresentation of nouns in children’s growing vocabulary was characteristic of English but not of all languages (e.g., Tardif,

1996) During this period, even as vocabulary emerged from total neglect, it was primarily of quantitative interest — number of words known — a measure that could be used to signal whether children were on a normal developmental track,

or to match groups on a developmental level Few child language researchers were asking which words children learned or what topics they were most inclined to be talking about

Which words?

The question of which words children learned was perhaps first raised by Katherine Nelson (1973), in her study of individual differences in early language acquisition She identified the more familiar, noun-learning child as typical for the referential group, which she contrasted with the less frequently described expres-sive group — children who learned a higher proportion of social expressions and socially useful phrases (e.g., thank you, don’t do that) Serious attention to which words were frequently acquired in the earliest stages of language acquisition was required, though, for another effort at using vocabulary size as a developmental indicator: the design of the MacArthur Communicative Development Inventory (CDI; Fenson, Dale, Reznick, Bates, & Thal, 1994), a parent-report instrument Eliciting information from caregivers about the size of their children’s vocabul-aries requires having a list of candidate words — thus was launched the first serious attempt to figure out which words children learn, though still in service of the question how many words they know The CDI has been extremely widely used, but users of CDI data rarely exploited the information about semantic categories or specific lexical items made available by the instrument

In addition to the CDI, transcript analysis continued to be the standard approach to studying children’s language development Automated transcript analysis systems such as the Systematic Analysis of Language Transcripts (SALT; Miller & Chapman, 1985) and the Child Language Data Exchange System (CHILDES; MacWhinney, 2000a, 2000b; MacWhinney & Snow, 1985,

1990) produced data that could be automatically mined to answer questions about the words children used, but a quick scan of the research published in child language-focused journals suggests rather limited use of the data for such pur-poses Targeted searches for specific words or categories of word (e.g., for politeness-related words like please and thank you, Snow, Perlmann, Gleason,

& Hooshyar, 1990; or for mental-state terms, Bartsch & Wellman, 1995) have generated important insights, but these have occurred most often in response to questions about children’s social or cognitive development Language researchers remain more focused on how children say things than on what they say

Vocabulary in interaction

Though the Hart and Risley study was instrumental in focusing attention on the input to children, in fact research had made abundantly clear long before they published their book that input to children was in many ways supportive of language learning The supportive features in language used with young children included phonological clarity (Ratner,1984,1987), high redundancy and syntactic simplicity (Snow, 1972), limitation to topics and propositions appropriate to children’s developmental level (Snow, 1977), presence of expansions on child utterances (Brown & Bellugi,1964) and a very gradual introduction of topics that went beyond the here and now (Snow,1984)

Subsequent work has made even clearer the features of adult-child interaction that support children’s language learning The use of gestures (Rowe, 2000), asking questions (Hoff-Ginsberg, 1986; Rowe, 2008), adopting dialogic styles

of book-reading (Mol, Bus, & de Jong, 2009), using lower frequency words in contexts that help clarify their meaning (Weizman & Snow, 2001) and talking responsively (Pan, Rowe, Singer, & Snow, 2005) all have been shown to be associated with better language outcomes or faster language learning for children Our knowledge base has expanded impressively — but still with remarkably little attention to what parents and children actually talk about! For instance, despite the extensive focus on book-reading as a context for language learning, and the suggestion that it works in part by introducing vocabulary and topics that expand the default list typical of natural interaction (Weizman & Snow, 2001), rather little attention has been paid in studies of language development to the specific words learned or the domains of content knowledge referred to in the books read The exception to this generalization comes from a growing body of research

on vocabulary interventions with young children (e.g., August, Artzi, & Barr,

2016; Loftus-Rattan, Mitchell, & Coyne,2016) In such studies, researchers have

no choice but to look at specific words — in general, the evidence suggests that children learn only the words taught in the intervention Efforts to use targeted interventions to expand general vocabulary (e.g., scores on the Peabody Picture Vocabulary Test, PPVT, or the Woodcock vocabulary assessment) have been largely unsuccessful, at least in the short run This is not surprising — standar-dized vocabulary assessments sample sparsely from a very large target domain, so the likelihood that children will learn precisely those words that get them higher scores on the test is very low Successful interventions can generate lots of word learning without showing impacts on tests that fail to include the curricular target words But their limited success reorients us to the question, what words should children be learning? Are some words more important than others? Is there a principled basis for organizing input to children beyond simply word frequency, which is the primary basis for selecting vocabulary test items?

Noticing the gap

Why did it take so long for the vocabulary gap to attract researchers’ attention and then, ultimately, become the target of intervention programmes and social action?

The impetus did not come, I would argue, from the child language community, but rather from those studying literacy development The finding that children’s vocabulary scores predict their reading success, both concurrently and predic-tively, is robust and widely replicated (Snow, Burns, & Griffin,1998) Social class differences in reading success are large and troubling, prompting an exploration of possible sources The evidence presented by Hart and Risley offered an explana-tion for the achievement gap in reading, and thus became an impetus to greater emphasis in early childhood programmes on vocabulary development

Of course, the Hart and Risley findings make very clear that sizable vocabu-lary discrepancies are present by age three — well before most children enter any educationally focused early childhood setting Thus the second wave of response

in grappling with those findings was a series of efforts to intervene with families

to ensure that all children’s language environments approach the verbal density and variety of those available to the highest SES group in the Hart and Risley study Examples of such efforts include Providence Talks, Denver Talks Back, The 30 million Words Initiative, Vroom [http://www.joinvroom.org/] and the efforts of organizations such as Zero to Three [http://main.zerotothree.org], the Parent-child Home Program [http://www.parent-child.org/] and Reach Out and Read [http://www.reachoutandread.org/] Some of these initiatives have shown measurable effects in large- or small-scale evaluation efforts, and none of them should be dismissed out of hand Of particular promise are the attempts to turn small screens (phones and tablets), which too often are used to deflect children’s conversational approaches to adults, into sources of support for adult-child con-versation Nonetheless, I argue that interventions focused primarily on amount of talk are likely to fail, unless they both build on child curiosity and provide adults resources for enriching the content of talk

The well-intentioned efforts

The many efforts underway to intervene in young children’s development, both those targeted at families during the first three years of life and those targeted at early childhood educators dealing with children as old as four or five, arise from excellent intentions to resolve the 30 million-word gap, i.e., to ensure that adults talk more to the children in their care This seems like a reasonable response to the data, but I will argue that it is misguided, on two grounds First, the SES gap that

we should be worrying about is a knowledge gap; vocabulary size is an index of knowledge, but the size of a child’s vocabulary is not important except to the extent that it signals something about conceptual or knowledge development Indeed, the excellent academic outcomes of second-language learners with strong first language skills strongly support the notion that ‘knowing the words’ is less important than knowing the concepts the words label Second, characterizing the problem as a word-gap leads to simplistic responses, e.g., telling parents just to talk more, or suggesting that preschool teachers put up word walls in their classrooms Such efforts are likely to have only the most marginal effects If parents interpret the advice about talking more to mean ‘repeat everything you say

a few times’, children’s language environments are denser but not richer Explicit vocabulary instruction in preschool is much less efficient than the natural voca-bulary acquisition that results from use of low frequency words during rich discussions about interesting topics Furthermore, focusing on vocabulary rather than knowledge can lead to counterproductive practices with second-language learners — suggesting more input in the school language, for example, rather than strengthening the learner’s knowledge base in any language whatsoever

A more robust and promising approach would be to explore the differences between conversations in well-resourced vs less-privileged households, to see how they differ in quality and content To be fair, Hart and Risley did this They presented in their book transcripts of parent-child talk that make clear the many dimensions of difference in talk that go along with differences in quantity of words (and subsequent research by many has confirmed those dimensions) Hart and Risley’s more highly educated, professional parents gave children more praise and fewer reprimands, produced more complex syntax and engaged in conversa-tions that focused over more turns on a single topic In other words, their talk differed from that of low-income parents on emotional, grammatical and discourse dimensions Nonetheless, the public presentation of their work has focused almost exclusively on numbers of words, not on which words or how those words are used

Next steps

What is wrong with ‘just talk more’ advice? It fails to take into account both what

we know about vocabulary development and the natural forces shaping adult-child interaction We know that vocabulary develops in the course of conversa-tion, that those conversations are relevant to ongoing activities and that children’s contributions have social-communicative goals At the earliest stages, for exam-ple, children (at least those in families with responsive adults) can initiate con-versations by pointing at objects, to which parents typically respond by naming the indicated item One might legitimately ask whether children aged

10–-18 months engage in pointing because they have the communicative intent to elicit names; very likely the more broadly social intent to share a joint focus of attention and/or to engage adults’ attention and direct their behaviour motivates their pointing Such interactions are described in Ninio and Bruner (1978) and in Ninio and Snow (1996) as games rather than conversations; though information is exchanged, that is not their primary purpose

As children’s language skills develop, these language games continue, but two additional types of communicative activity come to play a central role in shaping the conversations of which they are a part: discussing a joint focus of attention (naming, identifying attributes of named items, talking about the pictures in a shared book, etc.); and negotiating immediate activity (talking about how to build

a tower or complete a jigsaw puzzle, making cookies, getting dressed, putting toys away) (Ninio & Snow, 1996) In these two categories of communicative exchange, the shared focus of attention or activity creates a visible, manageable,

comprehensible structure into which words fit and through which they become learnable

Slightly older children no longer need the scaffold of the external activity as a context for understanding words; they are capable of engaging in extended dis-courses — narratives, explanations, discussions — through which new words can

be learned, but even more importantly both previously familiar and new, unfamiliar words can be put into larger conceptual and semantic contexts (Nelson, 2013) Thus, a four-year-old might well learn the word ‘oxygen’ from a discussion of the firefighters’ visit to his daycare class, but probably not from the periodic table or a listing of atmospheric gases And the discussion of the firefighter visit will link oxygen semantically and conceptually to an array of words related to the firefighting scenario: fire, fire engine, face mask, oxygen tank, protection, rescue, respiration, asphyxiation and perhaps, if the adults are sufficiently attentive and sesquipedalian, conflagration, catastrophe, oxidation and inferno This is one natural context for vocabulary learning — an interesting conversation about a personally experienced event It is, furthermore, an opportunity for young children to start to acquire the information structures that will support their reading comprehension and ongoing learning in school contexts many years later Thus a discussion of firefighters’ oxygen masks opens up a possibility to learn about the utilization of oxygen in fires,

a short step to understanding the chemistry of rapid oxidation

Another natural context for vocabulary learning is created by children’s ques-tions Michelle Chouinard (2007) conducted an analysis of transcripts of parent-child conversations from five parent-children between the ages of 18 and 60 months She reported that the children asked between 50 and 120 questions per hour, the vast majority of which were information-seeking questions While not all those ques-tions initiated rich conversaques-tions, the majority were answered by the adults, and indeed if they were not answered the children persisted, repeating their questions much more often than they repeated their own statements In other words, at about

18 months children start to show their interest in acquiring information, and thus craft for themselves rich opportunities to learn vocabulary in the context of connected discourse Of course, acquiring vocabulary is not the children’s intent; they are interested in certain topics — the words come along for free! But again, children from lower SES families are less likely to get informative responses to their information questions, and ultimately become less likely to persist in demanding such responses, having learned from earlier interactions that parents

do not reward curiosity (Kurkul & Corriveau, in press)

Implications

Everything we know about vocabulary acquisition suggests strongly that children acquire large vocabularies in the context of responsive interactions about topics of interest to them ‘More language input’ all by itself will not close the 30 million-word gap; it will take better language input, input more adapted to child interests and input in the context of which rich conceptual structures can be built Children build knowledge about topics of interest to them (Engel,2015), but most reliably

when those topics are shared with adults, in discussions and negotiations about content Dinner table conversations about what happened during the day as well

as about where food comes from, why we need vegetables in our diet and what is happening tomorrow generate opportunities for children to ask questions about what words mean, about how things work and about why people act the way they

do Reading aloud and discussing books of interest to children create rich contexts for informative conversations, in part because the books often supplement and broaden the knowledge and language available to the adult Shared special events — things like excursions to the beach, visits to the zoo, going to museums

or celebrating holidays with family members — create opportunities for new learning and for developing reminiscence narratives with adults, during which vocabulary gets built At the same time, though, more quotidian activities such as getting dressed, fixing meals, buying groceries or taking a bus to an appointment can also create contexts in which talk about what is going on builds knowledge about how the world works Such conversations constitute situations in which language is linked to content, in which knowledge structures are built and elaborated and in which, because they get answers to the questions they pose, children become increasingly curious Those are the real mechanisms for building better brains

El papel del vocabulario frente al conocimiento en el aprendizaje lingüístico de los niños: una perspectiva de cincuenta años

Recientemente educadores de la primera infancia y activistas políticos han apro-vechado el meme ‘brecha de 30 millones de palabras’ para llamar la atención sobre las diferencias de clase social en el vocabulario de los niños (ver por ejemplo Suskind, 2015) Los 30 millones de palabras que separan a los niños más privilegiados de aquellos que viven en la pobreza y en hogares de bajo nivel de alfabetización no se refieren, por supuesto, a sus propios vocabula-rios, sino a la cantidad de palabras que han tenido oportunidad de escuchar para cuando llegan a su tercer cumpleaños Un estudio llevado a cabo en los años ochenta por Betty Hart y Todd Risley, y publicado en el libro Meaningful Differences in the Everyday Experience of Young American Children (1995), mostraba que los niños que crecen en circunstancias de menor privilegio tienen menos oportunidades, en muy diversos niveles, de escuchar lenguaje: en prome-dio, sus padres pasan menos tiempo jugando con ellos y hablándoles; cuando están con sus hijos, los padres de familias de bajos ingresos típicamente hablan menos, y sus enunciados son más escasos y más cortos; y también responden con menor frecuencia a las iniciativas comunicativas de sus hijos Además, es mucho menos probable que los padres de clase media (respecto a los padres de bajos ingresos) les digan a sus hijos que se callen o que les nieguen sus peticiones sin una explicación, y más probable que les dediquen palabras de aliento y elogio Si

se calculan las diferencias observadas en grabaciones normales de vídeo de una hora de duración tomadas regularmente a lo largo de más de dos años, y extra-polando a una edad de cinco años, se puede estimar que, efectivamente, los niños

de hogares menos enriquecidos lingüísticamente escuchan 30 millones de palabras menos que los niños de padres profesionales con un nivel superior de educación Los hallazgos de Hart y Risley se publicaron en 1995, pero pasaron casi 20 años hasta que comenzaron a ejercer una influencia visible y firme sobre la opinión pública, las prácticas y políticas de educación temprana Hasta 2016 se habían citado más de 5,000 veces, y han servido de eslogan para un amplio abanico de iniciativas en política social En este artículo abordo el contexto histórico de los hallazgos de Hart y Risley, revisando brevemente la historia del pensamiento sobre el desarrollo del vocabulario a partir de mis propias investi-gaciones y de las de otros expertos en el área, para después tratar de determinar si

el énfasis actual sobre el vocabulario en la educación de niños pequeños está bien fundamentado Dada la influencia que está ejerciendo este énfasis sobre la dotación de fondos, diseños de programas y formación de políticas, es