Vocabulary development in Greek children: a cross-linguistic comparison using the Language Development Survey

Lexical development in Kuwaiti Arabic in typically developing children and late talkers

INTRODUCTION

This study explored vocabulary development and lexical composition in young typically developing (TD) Kuwaiti children and late talkers (LT) using the Kuwaiti Arabic Communicative Development Inventory-Words and Sentences (KACDI-WS) Abdalla et al., 2016). The sample included 161 children aged 20 to 37 months: 127 TD and 34 children who were late talkers (LT group). The late talkers were first identified based on a background questionnaire answered by the parents. All the caregivers completed a 698-item web-based KACDI expressive vocabulary inventory by selecting non-imitative words that their children produced.

RESULTS

Lexical size and composition (nouns, predicates, and closed-class words) were analyzed. Across the TD age groups (20-26, 27-31, 32-37 months), a significant age effect for vocabulary size and composition was found in favor of the older groups. Nouns were more prevalent than predicates or closed-class words in within-group comparisons. The vocabulary size of the TD (M= 263.8) was significantly larger than that of the LT group (M= 69.2). The development of their lexical composition followed a similar pattern.

CONCLUSIONS

The results suggested that the KACDI parent report instrument has the potential for measuring vocabulary development in TD children and could serve as an initial screening tool to identify late talkers.

It's All in the Interaction: Early Acquired Words Are Both Frequent and Highly Imageable

Prior studies have found that children are more likely to learn words that are frequent in the input and highly imageable. Many theories of word learning, however, predict that these variables should interact, particularly early in development: frequency of a form is of little use if you cannot infer its meaning, and a concrete word cannot be acquired if you never hear it. The present study explores this interaction, how it changes over time and its relationship to syntactic category effects in children acquiring American English. We analyzed 1461 monolingual English-speaking children aged 1;4-2;6 from the MB-CDI norming study (Fenson et al., 1994). Word frequency was estimated from the CHILDES database, and imageability was measured using adult ratings. There was a strong over-additive interaction between frequency and imageability, such that children were more likely to learn a word if it was both highly imageable and very frequent. This interaction was larger in younger children than in older children. There were reliable differences between syntactic categories independent of frequency and imageability, which did not interact with age. These findings are consistent with theories in which children's early words are acquired by mapping frequent word forms onto concrete, perceptually available referents, such that highly frequent items are only acquired if they are also imageable, and vice versa.

A Greek Pediatric Word Recognition Test by Picture Identification

(1) Background: The study aimed to construct a clinically valuable closet-set WRS test with a picture identification task for young Greek-speaking children. (2) Methods: The test material was meticulously designed based on specific criteria. To determine which parts of speech are used more frequently by preschool children, a spontaneous speech sample (250 words per child) was acquired from three hundred children aged 3 to 6 years (M = 4.56, SD = 0.90). The study involved the development and application of two phonemically balanced 50-word lists suitable for young children, as well as the creation of picture representations for each response set. All testing was accomplished in an audiometric booth that exceeded the audiometric rooms' ambient noise level standards. The speech signal was routed from a laptop computer to a GSI 61 audiometer, and all test items were delivered from the audiometer to the subject. (3) Results: The results indicated that materials for a WRS test for young children are developed with high face validity and are applicable for children as young as three years old. The test satisfies the essential components needed for a WRS test. It consists of two phonemically balanced 50-word lists with low-redundancy bisyllabic words, with each list containing 227 phonemes. (5) Conclusions: This novel closed-set WRS test presents a valuable tool for assessing speech perception skills in young Greek-speaking children. The test results have various applications, including diagnosis, research, and (re)habilitation.

Psychometric Properties of the Cyprus Lexical List in the Greek Language for Infants and Preschool Children and Preliminary Results

The aim of this study was to evaluate the psychometric properties of the adapted Cyprus Greek Lexical List a-CYLEX (GR) in a sample of 194 Greek toddlers from the island of Crete with Standard Modern Greek (SMG) as their primary language. The a-CYLEX (GR) is a parental report checklist for assessing the receptive and expressive vocabulary skills of children aged 12 months to 3:6 years. Concurrent validity of the instrument was tested via correlations with the adapted Greek version of the Receptive One-Word Picture Vocabulary Test-II (ROWPVT-II), which was administered to 124 SMG-speaking children between the ages of 2 and 3:6 years. Test-retest reliability was tested by administering the instrument two times within a 2-week interval to 59 parents (30.41% of the total sample). Statistical analyses provided strong evidence for the high internal consistency and test-retest reliability of the a-CYLEX (GR). The role of the demographic variables in vocabulary performance and the frequency of each a-CYLEX (GR) word category by age were also investigated. In conclusion, the a-CYLEX (GR) is a parental report checklist that can be used by clinicians who are interested in assessing receptive and expressive vocabulary of children during toddlerhood.

Early language and communication development in Chinese children: Adaption and validation of a parent report instrument

PURPOSE

To fulfil the needs of assessment tools in the Chinese population, we adapted the LENA Developmental Snapshot, a parent survey that measures early language and communication development in English-speaking children. We reported the psychometric properties of the adapted questionnaire and evaluated the metric and functional equivalence between the adapted and the original instruments.

METHOD

The Snapshot was translated into Chinese and reviewed by an expert panel. English-specific items (e.g. past tense, plural) were mapped onto functionally similar Mandarin vocabulary and structures. The questionnaire was administered to 1300 families with children ages 2-48 months. The Bayley Scales of Infant Development was administered to a subsample.

RESULT

Scores on the adapted questionnaire showed age-related increases in the 7-36 month age range and correlated with scores on the Chinese Bayley. The questionnaire showed high internal consistency and split-half reliability. Comparison with the US norm revealed slightly lower performance in the current sample. Adaptations of English-specific items resulted in functionally equivalent targets.

CONCLUSION

Despite differences in linguistic roots, the Chinese adaption of the LENA Snapshot captured developmental changes in children's language and communication abilities. Additional norming and validation efforts are needed in a more representative sample.

Online comprehension across different semantic categories in preschool children with autism spectrum disorder

Background

Word comprehension across semantic categories is a key area of language development. Using online automated eye-tracking technology to reduce response demands during a word comprehension test may be advantageous in children with autism spectrum disorder (ASD).

Objectives

To measure online accuracy of word recognition across eleven semantic categories in preschool children with ASD and in typically developing (TD) children matched for gender and developmental age.

Methods

Using eye-tracker methodology we measured the relative number of fixations on a target image as compared to a foil of the same category shown simultaneously on screen. This online accuracy measure was considered a measure of word understanding. We tested the relationship between online accuracy and offline word recognition and the effects of clinical variables on online accuracy. Twenty-four children with ASD and 21 TD control children underwent the eye-tracking task.

Results

On average, children with ASD were significantly less accurate at fixating on the target image than the TD children. After multiple comparison correction, no significant differences were found across the eleven semantic categories of the experiment between preschool children with ASD and younger TD children matched for developmental age. The ASD group showed higher intragroup variability consistent with greater variation in vocabulary growth rates. Direct effects of non-verbal cognitive levels, vocabulary levels and gesture productions on online word recognition in both groups support a dimensional view of language abilities in ASD.

Conclusions

Online measures of word comprehension across different semantic categories show higher interindividual variability in children with ASD and may be useful for objectively monitor gains on targeted language interventions.

Polish Vocabulary Development in 2-Year-Olds: Comparisons With English Using the Language Development Survey

PURPOSE

The objective of this study was to compare vocabulary size and composition in 2-year-olds learning Polish or English as measured by the Language Development Survey (LDS; Rescorla, 1989).

METHOD

Participants were 199 Polish toddlers (M = 24.14 months, SD = 0.35) and 422 U.S. toddlers (M = 24.69 months, SD = 0.78).

RESULTS

Test-retest reliability was .92, internal consistency was .99, and concurrent validity was .55. Girls had higher vocabulary scores than boys. Mean LDS score was significantly lower in Polish than in English, and fewer Polish children had LDS scores >200 words. Also, more words were reported for <25% of the children, and fewer words were reported for ≥75% of the children, in Polish than in English. The cross-linguistic correlation for word frequencies was .44. Noun dominance was comparable in the two languages, and 55 cross-linguistic word matches were found among the top 100 words. Although more Polish than U.S. children had <50 words (18.1% vs. 8.3%), children with <50 words and those with ≥50 words were generally acquiring the same words.

CONCLUSIONS

Vocabulary acquisition appeared to be slower in Polish than in English, probably because of the complexity of the language. However, the languages were very similar with respect to vocabulary composition findings.

Do early noun and verb production predict later verb and noun production? Theoretical implications

Many studies have addressed the question of the relative dominance of nouns over verbs in the productive vocabularies of children in the second year of life. Surprisingly, cross-class (noun-to-verb and verb-to-noun) relations between these two lexical categories have seldom been investigated. The present longitudinal study employed observational and parent-report data obtained from thirty mother-child dyads at 1;4, 1;8, and 2;0 to examine this issue. Both the Natural Partitions/Relational Relativity (NP/RR) hypothesis and the Emergentist Coalition Model (ECM) predict that having an initial repertoire of common nouns should facilitate the acquisition of novel verbs, whereas only the ECM suggests that children exploit the syntactic and semantic constraints of known verbs to infer the meaning of novel nouns. In line with the ECM, hierarchical regression analyses indicated that the percentages of nouns produced by children at 1;4 predicted later verbs at 1;8, whereas the percentages of verbs produced at 1;8 predicted later nouns at 2;0.

Vocabulary Development in European Portuguese: A Replication Study Using the Language Development Survey

PURPOSE

Our objective was to replicate previous cross-linguistic findings by comparing Portuguese and U.S. children with respect to (a) effects of language, gender, and age on vocabulary size; (b) lexical composition; and (c) late talking.

METHOD

We used the Language Development Survey (LDS; Rescorla, 1989) with children (18-35 months) learning European Portuguese (n = 181) and English (n = 206).

RESULTS

In both languages, girls had higher vocabulary scores than boys and vocabulary scores increased with age. Portuguese LDS scores were significantly lower than English scores, but the effect size was small. Cross-linguistic concordance of percentage use scores yielded a Q correlation of .50, with 64 of the "top 100" words being exact matches. Cross-linguistic concordance was highest for the youngest age group. In both languages, vocabulary composition in late talkers (children ≥ 24 months with < 50 words) was highly correlated with composition in vocabulary size-matched younger children.

CONCLUSIONS

Results replicated previous Greek, Korean, and Italian LDS studies. The early lexicons of typical talkers and late talkers contained many of the same words, indicating considerable universality and suggesting good targets for clinical intervention.

Noun and Verb Production in Maternal and Child Language: Continuity, Stability, and Prediction across the Second Year of Life

The present study examined continuity/discontinuity and stability/instability of noun and verb production measures in 30 child-mother dyads observed at 16 and 20 months, and predictive relations with the acquisition of nouns and verbs at 24 months. Children exhibited significant discontinuity and robust stability in the frequency of nouns and verbs between 16 and 20 months (over and above the contribution of maternal measures). By contrast, mothers showed small, but significant, increases in the total number of nouns and the percentages of nouns located in the initial and final utterance positions, together with a decrease in the percentage of verbs located in the initial position. After removing the variance explained by child language, mothers' speech was stable only in the percentages of nouns located in the initial and final utterance positions. Finally, children's production of nouns at 24 months was predicted by the percentages of nouns located in the initial and final positions of maternal utterances at 16 months. Maternal measures at 20 months did not predict children's production of nouns nor for verbs at 24 months. Implications for language acquisition are discussed.

Children's acquisition of nouns and verbs in Italian: contrasting the roles of frequency and positional salience in maternal language

Because of its structural characteristics, specifically the prevalence of verb types in infant-directed speech and frequent pronoun-dropping, the Italian language offers an attractive opportunity to investigate the predictive effects of input frequency and positional salience on children's acquisition of nouns and verbs. We examined this issue in a sample of twenty-six mother-child dyads whose spontaneous conversations were recorded, transcribed, and coded at 1;4 and 1;8. The percentages of nouns occurring in the final position of maternal utterances at 1;4 predicted children's production of noun types at 1;8. For verbs, children's growth rates were positively predicted by the percentages of input verbs occurring in utterance-initial position, but negatively predicted by the percentages of verbs located in the final position of maternal utterances at 1;4. These findings clearly illustrate that the effects of positional salience vary across lexical categories.

Typical and delayed lexical development in Italian

PURPOSE

The Language Development Survey (LDS; Rescorla, 1989) was used to compare Italian and English lexical development. The authors addressed the issue of universal versus language-specific aspects of lexical development by testing language, age, and gender effects on vocabulary scores and by comparing vocabulary composition across languages. They addressed the issue of delay versus deviance by comparing vocabulary composition in late talkers and younger vocabulary-size-matched children.

METHOD

Participants were 398 Italian and 206 U.S. children ages 18-35 months.

RESULTS

Vocabulary size did not differ significantly by language, and age and gender effects on vocabulary size were not moderated by language. The Italian-English Q correlation for percentage word use scores was .55, lower than the within-language concordance of .90 and above. Cross-linguistic concordance declined as age and vocabulary size increased. Many cross-linguistic word matches (63 words) were found among the top 100 words. Italian late talkers were similar to younger vocabulary-size-matched Italian children in vocabulary composition, consistent with findings for English, Greek, and Korean.

CONCLUSIONS

In both languages, the early lexicons of late talkers and typical talkers contained many of the same words, indicating considerable universality in young children's lexical development. These common words are therefore good targets for clinical intervention.

Lexical development in Korean: vocabulary size, lexical composition, and late talking

PURPOSE

In this study, the authors aimed to compare vocabulary size, lexical composition, and late talking in large samples of Korean and U.S. children ages 18-35 months.

METHOD

Data for 2,191 Korean children (211 children recruited "offline" through preschools, and 1,980 recruited "online" via the Internet) and 274 U.S. children were obtained using the Language Development Survey (LDS).

RESULTS

Mean vocabulary size was slightly larger in the offline than the online group, but the groups were acquiring almost identical words. Mean vocabulary size did not differ by country; girls and older children had larger vocabularies in both countries. The Korean-U.S. Q correlations for percentage use of LDS words (.53 and .56) indicated considerable concordance across countries in lexical composition. Noun dominance was as large in Korean lexicons as in U.S. lexicons. About half of the most commonly reported words for the Korean and U.S. children were identical. Lexicons of late talkers resembled those of typically developing younger children in the same sample.

CONCLUSIONS

Despite linguistic and discourse differences between Korean and English, LDS findings indicated considerable cross-linguistic similarity with respect to vocabulary size, lexical composition, and late talking.

Lexical composition in children with autism spectrum disorder (ASD)

For sixty-seven children with ASD (age 1;6 to 5;11), mean Total Vocabulary score on the Language Development Survey (LDS) was 65·3 words; twenty-two children had no reported words; and twenty-one children had 1-49 words. When matched for vocabulary size, children with ASD and children in the LDS normative sample did not differ in semantic category or word-class scores. Q correlations were large when percentage use scores for the ASD sample were compared with those for samples of typically developing children as well as children with vocabularies <50 words. The 57 words with the highest percentage use scores for the ASD children were primarily nouns, represented a variety of semantic categories, and overlapped substantially with the words having highest percentage use scores in samples of typically developing children as well as children with lexicons of <50 words. Results indicated that the children with ASD were acquiring essentially the same words as typically developing children, suggesting delayed but not deviant lexical composition.