Child Mean Length Of Utterance Research Articles

The effects of family, culture and sex on linguistic development across 20 languages.

Languages vary in their complexity; caregivers vary in the way they structure their communicative interactions with children; and boys and girls can differ in their language skills. Using a multilevel modelling approach, we explored how these factors influence the path of language acquisition for young children growing up around the world (mean age 2-years 9-months; 56 girls). Across 43 different sites, we analysed 103 mother-child pairs who spoke 3,170,633 utterances, 16,209,659 morphemes, divided across 20 different languages: Afrikaans, Catalan, Cantonese, Danish, Dutch, English, Farsi, French, German, Hebrew, Icelandic, Irish, Italian, Japanese, Mandarin, Norwegian, Portuguese, Spanish, Swedish and Turkish. Using mean length of utterance (MLU) as a measure of language complexity and developmental skill, we found that variation in children's MLU was significantly explained by (a) between-language differences; namely the rate of child MLU growth was attuned to the complexity of their mother tongue, and (b) between-mother differences; namely mothers who used higher MLUs tended to have children with higher MLUs, regardless of which language they were learning and especially in the very young (<2.5 years-old). Controlling for family and language environment, we found no evidence of MLU sex differences in child speech nor in the speech addressed to boys and girls. By modelling language as a multilevel structure with cross-cultural variation, we were able to disentangle those factors that make children's pathway to language different and those that make it alike. RESEARCH HIGHLIGHTS: The speech of 103 mother-child pairs from 20 different languages showed large variation in the path of early language development. Language, family, but not the sex of the child, accounted for a significant proportion of individual differences in child speech, especially in the very young. The rate at which children learned language was attuned to the complexity of their mother tongue, with steeper trajectories for more complex language. Results demonstrate the relative influence of culture, family, and sex in shaping the path of language acquisition for different children.

Mean Length of Utterance and Other Quantitative Measures of Spontaneous Speech in Russian-Speaking Children.

Purpose This study investigated methodological and theoretical aspects of using mean length of utterance (MLU) and its alternatives in cross-linguistic research and, in particular, its applicability to Russian-a language with a rich system of grammatical and derivational morphemes. Method We collected audio recordings of spontaneous speech samples from 27 Russian-speaking children aged between 2;9 and 5;7 (years;months) over individual play sessions. For each participant, we transcribed the first 100 complete utterances and coded them for several types of utterance length measurements, including length in morphemes (grammatical and derivational), words, and syllables. At a sample level, we calculated the average number of produced unique grammatical forms, getting an alternative quantitative estimate of children's morphosyntactic abilities. Results A combination of Pearson correlation analysis and Bland-Altman difference plots established that MLU can be reliably used in Russian-speaking children aged around 3;0. The average number of unique grammatical forms remains a sensitive measurement of language capabilities even in older children aged over 3;6. Two quantitative measurements, MLU in syllables and morphemes, show good agreement, suggesting that these measurements can be used interchangeably across studies. Sample size analysis revealed that samples under 75 utterances do not provide sufficient reliability for estimating a child's MLU. Conclusions This article demonstrated that MLU can be used in young Russian-speaking children under 3;0-3;6. Also, we showed that the classical morpheme calculation approach can be substituted with counting syllables, which is more time efficient in the absence of automated parsers and is potentially more appropriate for some (e.g., polysynthetic) languages. Our proposed alternative to MLU-the average number of grammatical forms in a sample-appears to be a more sensitive measurement of language capabilities even in older children.

The influence of siblings on toddlers’ mean length of utterance

Linguistic complexity is an indicator of language development in young children. Complexity of a child’s linguistic productions have been shown to increase with development, but may be affected by factors such as disability or environmental variables. Here, we look into the role of family composition as a possible influence on a child’s developing ability to use increasingly complex language. In particular, we ask if a toddler’s mean length of utterance (MLU) is affected by the presence of siblings in the family and whether the sex of the child may play a role. MLU values were extracted from the public HomeBank database [http://homebank.talkbank.org] of transcribed natural child speech for both the target toddler and for siblings present in the recordings. Results indicate a main effect of increased MLU in children without siblings, but interaction effects suggest that differences may be driven by the boys without siblings alone. There was no correlation between the MLU of the target child and the MLU of ...

Assessing the impact of conversational overlap in content on child language growth.

When engaged in conversation, both parents and children tend to re-use words that their partner has just said. This study explored whether proportions of maternal and/or child utterances that overlapped in content with what their partner had just said contributed to growth in mean length of utterance (MLU), developmental sentence score, and vocabulary diversity over time. We analyzed the New England longitudinal corpus from the CHILDES database, comprising transcripts of mother-child conversations at 14, 20, and 32 months, using the CHIP command to compute proportions of utterances with overlapping content. Rates of maternal overlap, but not child overlap, at earlier time-points predicted child language outcomes at later time-points, after controlling for earlier child MLU. We suggest that maternal overlap plays a formative role in child language development by providing content that is immediately relevant to what the child has in mind.

Mean length of utterance (MLU) in typically-developing 2.5-5.5 year-old Persian-speaking children in Iran

Introduction: Mean length of utterance in morphemes (MLU) is widely used as a general index of language development in pre-school children. Because of insufficient data on Persian language development in Iran, this study examined the MLU of Persian-speaking children and its relation to their in an attempt to help improving clinical decision making. Materials and Methods: This cross-sectional study was conducted on 171 typically-developing children 2.5-5.5 years of age who were recruited from nursery settings of Isfahan, Iran. The sample was selected using a mixed method of sampling and divided into six age groups. After an informal conversation with each child to gauge whether the child appeared to be typically developing in terms of language and cognitive levels, speech therapists played with and tape-recorded them. Each child's MLU was calculated for 75 complete and intelligible utterances longer than one word. The mean and standard deviation of MLU were computed for each age group within six-month intervals. The correlation between age and MLU was also investigated. Results: The children’s mean MLU increased between 37-42 and 43-48 months and also between 43-48 and 49-54 months of age. The increase in MLU from the first age group onward was statistically significant. The correlation between age in months and MLU in morphemes was significant, r (171) = 0.47, P < 0.005. Conclusion: The average MLU of the children in this study-and similar studies of Persian-speaking children is much higher than that reported for English-speaking children, and the correlation with age lower; mainly because of morpho-syntactic differences between languages. Age sensitivity of MLU in Persian, however, indicates its capability as a developmental scale for monitoring syntax development in Persian-speaking children which needs to be deeply investigated in relation to Persian language-specific features, either. Keywords: Mean length of utterance, Syntax development, Language development, Pre-school children, Speech therapy

Inferential talk during teacher–child interactions in small-group play

This study examined teachers’ questions and children's responses during a play-based activity implemented in small groups within preschool classrooms. The first aim of this study was to describe teachers’ questions in terms of four levels of abstraction (i.e., a continuum of literal to inferential questions) and children's responses to these questions. The second aim was to examine the relations between teachers’ questions and children's responses using sequential analyses, to include children's level of abstraction and mean length of utterance (MLU). Participants were 39 teachers and up to six children from their preschool classroom. We found that teachers’ questions made up an average of 25% of their talk to children during play, and were relatively balanced between literal and inferential questions. Furthermore, significant sequential associations were found between the level of abstraction of teachers’ questions and the level of abstraction of children's responses (e.g., teachers’ inferential questions tended to elicit children's inferential responses). Finally, we found that teachers’ inferential questions were not related to children's MLU; that is, teachers’ more abstract questions did not elicit longer utterances from children. These findings suggest that play is a valuable context in which teachers may promote children's use of inferential language.

Verbal inflection, articles and object clitics in Italian specific language impairment

Morphosyntactic skills in spontaneous and elicited production of a 7-year-old boy with specific language impairment (SLI) were examined and compared to those of younger, mean length of utterance (MLU)-matched, typically-developing children. This study focused on inflectional phrase structures as well as complex constructions in order to investigate hypotheses which suggest verbal inflection is a key deficit underlying SLI. It analysed the most affected morphemes in Italian: articles and direct and indirect object clitics. A deficit was found in verbal inflection as well as in articles and object clitics. The difficulties with verbal inflection found were expected given the child's MLU. Problems with articles and clitics were unexpected for MLU, presenting a challenge for hypotheses that focus on verbal inflection.

Relationships between speech perception abilities and spoken language skills in young children with hearing loss

The goal of this study was to examine the relationships between scores obtained from measures of speech perception and language in a group of young children with hearing loss (HL). Eighteen children (mean age = 4.3 years) and their mothers participated in this study. Speech perception was measured using the online imitative test of speech pattern contrast perception (OLIMSPAC). Standardized language age equivalent scores were obtained using the Reynell developmental language scales-III. Number of word tokens, word types, and mean length of utterance (MLU) were extracted from the children's spontaneous language samples. Significant positive relationships were observed between children's OLIMSPAC scores and both standardized language scores (r ranging from 0.60 to 0.69; p <0.01) and all measures derived from children's spontaneous language samples (r ranging from 0.80 to 0.86; p<0.01). After controlling for child age, OLIMSPAC scores explained 34.1% of the variance in children's MLU. Using a new speech perception measure with reduced language demands, strong positive correlations were evident between speech perception and language skills for a young group of children with HL.

An etholinguistic analysis of mother-child discourse at 30 months

Ethological models of social development stress that diversity in early experience induces stylistic variation in patterns of early communication. Variation in children's speech was examined in a sample of 44 French-speaking mother–child dyads, filmed at home during semi-structured play when the children were 30 months of age. Eight speech act categories were used to describe the language of both partners. In addition, measures of the relative use of nouns, verbs, adjectives, adverbs, and pronouns, as well as child mean length of utterance were tabulated from transcribed verbal exchanges. Cluster analyses of relative frequency of speech acts revealed five sub-groups of children with distinct speech profiles. Three clusters differed on referential categories of speech and two clusters were distinguished on affective expressive dimensions. Expressive children had a more diversified lexicon. Mothers of referential children spoke most often using predominantly descriptive statements and attention requests. In contrast, mothers of expressive children asked for descriptive information more often and used more playful expressive speech. The typological analysis of individual differences in early communication provides a complement to normative assessments of developmental milestones in language acquisition. Such an approach provides the possibility of integrating psycholinguistic studies of language acquisition with ethological concerns about processes shaping early behavioral development.

Acquisition of irregular past tense by children with specific language impairment.

In this paper we add to what is known about the tense-marking limitations of children with specific language impairment (SLI) by exploring the acquisition of regular and irregular past tense, encompassing the age range of 2;6 to 8;9 (years;months) and comparing the performance of 21 children with SLI to that of 23 control children of the same age and 20 younger control children of equivalent mean length of utterance (MLU) at the outset. The analysis differentiated between the morphophonological component of past tense marking and the morphosyntactic component (finiteness). In the morphosyntactic component, the performance of the SLI group trails that of the two control groups over 3.5 years, whereas in the morphophonological component, the SLI group's performance is equivalent to that of the younger controls. Models of growth curves for regular past tense and irregular finiteness marking show the same pattern, with linear and quadratic components and the child's MLU at the outset as the only predictor. For morphophonological growth the picture changes, with an interaction of linear trend and MLU and the child's receptive vocabulary emerging as a predictor. The findings support a morphosyntactic model, such as the extended optional infinitive (EOI) model, with regard to the limitations in finiteness marking and for affected children.

Correlates and antecedents of maternal expansions of utterances of children with language disabilities

Fifty-one children with language delays, and their mothers, were studied to identify characteristics of the children's utterances that potentially influence an aspect of maternal linguistic input: expansions. A subset of 33 of these dyads was studied and submitted to sequential analysis to identify the types of child utterances mothers were most likely to expand. Twenty-minute mother-child free-play sessions were videotaped and transcribed. Trained observers coded utterances for child intelligibility, child topic maintenance, adult expansions, and adult non-expansions. The extent to which mothers expanded child utterances increased with increasing child mean length of utterance (MLU) and intelligibility. Moreover, mothers expanded multiword fully intelligible child utterances more than they did partially intelligible or single-word child utterances. The implications of the results for language intervention and future research are discussed.

Effect of Verbal Routine Contexts and Expansions on Gains in the Mean Length of Utterance in Children With Developmental Delays

This study tests the hypothesis that verbal routines and expansions increase generalized child mean length of utterance (MLU). Verbal routines were built through repeated interaction with the same picture book across several intervention sessions. The subjects were four young children with developmental delay. One of the subjects experienced two rounds of the intervention (i.e., two intervention phases with two different books) to provide the opportunity for more replication and extension of the effects. Generalization sessions were conducted with a different adult, different modality of material (i.e., objects), and different interaction style than were used during the intervention. The pattern of the results provides strong evidence that the intervention increased generalized MLU in children in the first stage of language development more than in children in a later language stage. The secondary analyses support the notion that verbal routines and expansions were responsible for the effects. Future research is needed to determine why the intervention was not effective for the developmentally older cases but was effective for the developmentally younger cases.

Mothers' lexicon of internal state words in speech to children with down syndrome and to nonhandicapped children at mealtime

This study examines internal state words in mothers' speech to children with Down syndrome, and the relation between the use of internal state words and the children's levels of social-adaptive, communicative, and linguistic functioning. Results indicate qualitative differences in mothers' use of internal state words to children with children Down syndrome, compared with a sample of maternal speech to nonhandicapped children who were matched on the Vineland scales for their level of adaptive functioning. Differences include use of fewer internal state words overall to children with Down syndrome, and different kinds of internal state words: more words referring to physiological states, and fewer words referring either to affect or to cognition. In general, child Mean Length of Utterance (MLU) was associated with the pattern of inner state words used by mothers, whereas no associations were found between children's social-adaptive competence and maternal input. Even when controlling for child MLU, there were, however, some qualitative differences in the inner state lexicons used to children with Down syndrome. Results suggest that speech to children with Down syndrome that is calibrated to their MLU may underestimate their competence in domains other than grammar.

A description of mothers' questions to their young deaf children during storybook reading.

The frequency and types of questions that four hearing mothers used with their 3- and 4-year-old deaf daughters was examined. Relationships between frequency and type of question and child mean length of utterance (MLU) measurements were also explored. Results indicated that the mothers used fewer questions than hearing mothers of hearing children but that the types of questions used were similar. Three mothers used text-related indirect commands, a question type not examined frequently in previous research. Child MLU measurements appeared to influence the amount and types of questions mothers used, although MLU, as measured in this study, may not have been a valid descriptor of the children's expressive language. Implications for the quality of language during joint book reading with young deaf children are discussed.

Development of language in 18—30-month-old HIV-1-infected but not ill children

Thirty-six children (age range, 18-30 months) born to HIV-1-infected mothers were studied for speech development by matching 18 infected with 18 non-infected subjects for age, sex and socioeconomic status. All the children were in good health. Each child was given three comprehension and three production tasks. In addition, each child's mean length of utterance (MLU) was obtained by observation of natural child-parent interactions. The development quotients (DQ) were assessed by Brunet-Lézine's tests. Infection significantly affected children's MLU, the infected children being less advanced than those non-infected. Both infected and non-infected children progressed in language acquisition from the second to the third year of age, but infected children had significantly greater production difficulty than non-infected children in the second year of life. The matched subjects design adopted gives some strength to the conclusion that HIV-1 infection impairs the genesis rather than the later development of language in infected but not ill children.

Conversation and Cooperation: Child Linguistic Maturity, Parental Speech, and Helping Behavior of Young Children

LAWRENCE, BARBARA M. Conversation and Cooperation: Child Linguistic Maturity, Parental Speech, and Helping Behavior of Young Children. CHILD DEVELOPMENT, 1984, 55, 1926-1935. The relationship between parental communicative behaviors, child linguistic maturity, and children's cooperative behavior was examined in a study of 60 children (20 each at approximately 18, 24, and 30 months of age) and their parents in a laboratory setting. Significant relationships were found between linguistic maturity of the children, the speech of the parents, and the children's helping behavior. Child mean length of utterance (MLU) was a better predictor of cooperative behavior than child age. No comparable relationships were found for parents' nonverbal behaviors. The results support a hypothesis of verbal mediation of this social behavior.