Early vocabulary development benefits from diverse lexical exposures within children's language environment. However, the influence of lexical diversity on children as they enter middle childhood and are exposed to multimodal language inputs remains unclear. This study evaluates global and local aspects of lexical diversity in three…

Research on "parentese," the acoustically exaggerated, slower, and higher-pitched speech directed toward infants, has mostly focused on maternal contributions, although it has long been known that fathers also produce parentese. Given recent societal changes in family dynamics, it is necessary to revise these mother-centered models of…

Research Findings: Early childhood teachers' talk is a key ingredient in children's early language and literacy development, but there has been little systematic synthesis of observational studies that examine relationships between teacher talk and child oral language. In this systematic review of 54 studies, we investigate and synthesize the…

One of the fundamental questions in the field of language acquisition is a learnability problem, which considers how learners acquire certain aspects of language which are not directly provided in the input or whose referents are not readily observable. This dissertation investigates Japanese children's acquisition of various linguistic phenomena,…

Children show a remarkable degree of consistency in learning some words earlier than others. What patterns of word usage predict variations among words in age of acquisition? We use distributional analysis of a naturalistic corpus of child-directed speech to create quantitative features representing natural variability in word contexts. We…

Phonological selectivity is a phenomenon where children preselect which target words they attempt to produce. The present study examines selectivity in the acquisition of complex onsets and codas in English, and specifically in the acquisition of biconsonantal (CC) clusters in each position compared to triconsonantal (CCC) clusters. The data come…

In this corpus study, it is asked whether young children speaking European French build their early syntax around grammatical or lexical words. Specifically, the study examines the relationship of grammatical and lexical words in three types of syntactic structures (determiner--noun, pronoun--verb and subject pronoun--verb). The corpus included…

This study investigates whether the earliest words children choose to say are mainly words containing sounds they can produce (cf. 'phonological dominance' hypotheses), or whether children choose words without regard to their phonological characteristics (cf. 'lexical dominance' hypotheses). Phonological properties of words in spontaneous speech…

Research Findings: The present study investigates both the proximal processes and contextual influences on children's oral language development in preschool. We examine whether teacher language practices vary across activity settings and program type, which teacher language practices predict children's oral language skills, and potential…

This paper provides an overview of the features of caregiver input that facilitate language learning across early childhood. We discuss three dimensions of input quality: interactive, linguistic, and conceptual. All three types of input features have been shown to predict children's language learning, though perhaps through somewhat different…

Purpose: Most educational assessments tend to be constructed in a close-ended format, which is easier to score consistently and more affordable. However, recent work has leveraged computation text methods from the information sciences to make open-ended measurement more effective and reliable for older students. This study asks whether such text…

Child language data are notoriously noisy. Children may produce several phonetic variants for a given word or use the same forms for several different words. As such, child data are characterized by little apparent systematicity. Competing theories have arisen to account for a range of problematic phenomena, but each has struggled to relate child…

Researchers have consistently found a link between the quality of early parent-child book-reading interactions and children's language skill. Two aspects of quality (level of abstraction and utterance function) were examined simultaneously in the current study to further refine our understanding of how parents' talk during shared reading predicts…

This study employs the Specificity Principle to examine the relative impacts of external (input quantity at home and at school, number of books and reading frequency at home, teachers' degree and experience, language usage, socioeconomic status) and internal factors (children's working memory, nonverbal intelligence, learning-related…

Fathers' child-directed speech across two contexts was examined. Father-child dyads from sixty-nine low-income families were videotaped interacting during book reading and toy play when children were 2;0. Fathers used more diverse vocabulary and asked more questions during book reading while their mean length of utterance was longer during toy…