Measures Of Lexical Diversity Research Articles

Speech and Language Skills of Low-Risk Preterm and Full-Term Late Talkers: The Role of Child Factors and Parent Input.

Among children in the third year of life, late talkers comprise from 9% to 20%. This range seems to increase when addressing preterm children. This study examined video-recorded child spontaneous speech during parent–child book sharing as well as linguistic skills reported through the MacArthur Bates Communicative Development Inventories (MB-CDI) Short Form in 61 late talkers aged 30 months old (26 low-risk preterm, 8 females; 35 full-term, 12 females). Differences between low-risk preterm and full-term late talkers in child language measures and parental speech input were tested, as were the roles of child and parent factors on child language. Low-risk preterm and full-term late talkers showed similar speech and language skills. Similarly, no differences were found in measures of parental speech between groups. Child cognitive score, chronological age, and low-risk preterm status were positively associated with lexical diversity, rate, and composition of child speech production, whereas family history for language and/or learning disorders as well as parent measures of lexical diversity, rate, and grammatical complexity were negatively associated with the above child variables. In addition, child cognitive score and low-risk preterm status were positively associated with the MB-CDI measures of word and sentence production. Findings are discussed in terms of the need of good practices when following up on low-risk preterm children and of interventions targeting parents’ input to preterm and full-term late talkers.

An Analysis of Text Difficulty across Grades in Korean Middle School English Textbooks Using Coh-Metrix

This study aims to investigate the text difficulty of the reading materials of Korean middle school English textbooks with Coh-Metrix, a software developed by the Institute for Intelligent Systems at the University of Memphis to analyze the linguistic and psycholinguistic features of English text and textbooks with a wide range of indices on cohesion and language. In this study, the textbook corpus consisted of the text files extracted from 13 English textbooks. These files were used for analyzing the text difficulty among grades with Coh-Metrix. The Coh-Metrix indices selected for this study contained basic counts, word frequency, word features, lexical diversity, pronouns, connectives, readability, syntax complexity, syntax similarity, reference cohesion, semantic cohesion, and situation model measures. The results showed that there were significant differences among grades for basic counts, word features, first pronouns, causal and temporal connectives, readability, reference and semantic cohesion, the number of words before main verbs, syntactic similarity, and situation model measures. The differences among grades, however, were not significant for word frequency, lexical diversity, second and third person pronouns, additive connectives, and NP density measures. The findings have educational implications for textbook design and language learning for English learners.

Planning conditions (strategic planning, task repetition, and joint planning), cognitive task complexity, and task type: Effects on L2 oral performance

The present study investigates the role of different planning conditions, cognitive task complexity along ± number of elements, and different task types in learners’ L2 oral performance. To this end, 98 Iranian learners at the intermediate level were randomly divided into four planning groups, namely, task repetition, strategic planning, joint planning (a combination of task repetition & strategic planning), and no planning. Each group performed simple and complex narrations and simple and complex argumentations. The data were scored based on measures of complexity, accuracy, lexical diversity, and fluency. The results indicated that in comparison with the simple tasks, the complex tasks promoted fluency, overall complexity, and lexical complexity, but lessened accuracy and subordination. Compared to the narrations, the argumentations brought about higher speech rate, more subordinated clauses, and greater lexical complexity. Strategic planning and task repetition enhanced fluency and syntactic complexity while their combination improved accuracy as well. The impact of task complexity was greater with the argumentations, and the utility of planning differed based on cognitive task complexity and the nature of task types. Some trade-offs were observed not only between accuracy and syntactic complexity but also between two measures of syntactic complexity, which supports the Trade-off Hypothesis.

Properties of Lexical Diversity in the Narratives of Children With Typical Language Development and Developmental Language Disorder.

Purpose We examined four measures of lexical diversity in the narratives of children with typical language development (TLD) and developmental language disorder (DLD) that comprised the normative sample of the Edmonton Narrative Norms Instrument (Schneider et al., 2005). The purpose was to document the properties of each measure with respect to variations in utterance and sample length, developmental trends, and group differences. Method The sample consisted of 377 picture-elicited, story generation transcripts from children with TLD (n = 300) and DLD (n = 77) aged 4-9 years. We extracted the moving-average type-token ratio (MATTR) and the number of different words from the full sample, from samples equated for the number of utterances, and from samples equated for the total number of words. Results MATTR was the only measure to show no relationships to utterance or sample length. All measures showed significant positive growth with age and significant groupwise differences between children with TLD and DLD. However, the magnitude of age effects and differentiation between groups varied considerably across measures. Across measures, there were significant differences in the number of children with DLD who were identified with low lexical diversity relative to their same-age peers in the TLD group. Conclusion The results of this study support the view that different measures of lexical diversity may be appropriate for different clinical purposes. It is important for clinicians to understand how measures of lexical diversity function in order to make educated choices among measures and ensure appropriate interpretation.

Lexical Diversity in Cypriot-Greek-Speaking Toddlers: A Preliminary Longitudinal Study

Background/Aims: The number of different words (NDW), an essential measure of lexical diversity, is extremely valuable towards providing data regarding children’s language development. However, in Cyprus, practitioners are deprived of the opportunity to utilize NDW, as no normative data exist for toddlers who speak Cypriot Greek (CYG). Methods: The language samples of 36 monolingual CYG-speaking toddlers (aged 36, 40, 44, and 48 months) with a typical course of language development were collected and quantitatively analyzed. Based on the language sample analysis, we ascertained typical NDW values at the aforementioned ages and tested through a linear mixed-effects model whether gender and age affected NDW. Results: The results showed that age significantly predicted NDW increase; gender did not emerge as a significant predictor of NDW, but this may be due to the small statistical power. Conclusion: This study intends to provide the first step towards longitudinal investigation of the level of NDW for CYG-speaking children with a typical course of language development. The provided data, which could serve as preliminary norms, may be used – under some restrictions for the time being – during language assessment. Moreover, these acquired data could contribute to the development of an NDW database for diverse CYG-speaking populations of different age ranges in the future.

Comparing Word Frequencies and Lexical Diversity with the ZipfExplorer Tool

The ZipfExplorer is a tool for the interactive comparison and visualization of shared word type frequencies for two texts or corpora. The tool can be used to give insight into similarities and differences in textual and discourse content in terms of individual keywords or groups of keywords, and also calculates several measures of lexical diversity for the shared types of the selected texts. A selection of texts and corpora can be analyzed, and users can upload their own files for interactive comparison.

Investigating the interrelationship between rated L2 proficiency and linguistic complexity in L2 speech

This study investigates the relationship between nine quantitative measures of L2 speech complexity and subjectively rated L2 proficiency by comparing the oral productions of English L2 learners at five IELTS proficiency levels. We carry out ANOVAs with pairwise comparisons to identify differences between proficiency levels, as well as ordinal logistic regression modelling, allowing us to combine multiple complexity dimensions in a single analysis. The results show that for eight out of nine measures, targeting syntactic, lexical and morphological complexity, a significant overall effect of proficiency level was found, with measures of lexical diversity (i.e. Guiraud’s index and HD-D), overall syntactic complexity (mean length of AS-unit), phrasal elaboration (mean length of noun phrase) and morphological richness (morphological complexity index) showing the strongest association with proficiency level. Three complexity measures emerged as significant predictors in our logistic regression model, each targeting different linguistic dimensions: Guiraud’s index, the subordination ratio and the morphological complexity index.

Lexical diversity and lexical skills in children who stutter

PurposeNumerous “small N” studies of language ability in children who stutter have produced differing conclusions. We combined test and spontaneous language data from a large cohort of children who stutter (CWS) and typically fluent peers, gathered from independent laboratories across the US, to appraise a variety of lexical measures. MethodStandardized receptive and expressive vocabulary test data and spontaneous language samples from 99 pairs of CWS (ages 25–100 months), and age-, gender-, and SES-matched children who do not stutter (CWNS) were compared. Language sample transcripts were analyzed with four measures of lexical diversity. Correlations between lexical diversity measures and expressive vocabulary scores were also calculated. ResultsOn standardized tests of both receptive and expressive vocabulary, there were significant differences between CWS and CWNS. In contrast, on spontaneous language measures of lexical diversity, CWS did not differ in their lexical diversity, across analyses, compared to CWNS. Three of the four lexical diversity analyses, MATTR, VocD, and NDW, were significantly correlated with each other. ConclusionsWe were able to confirm prior findings of relative disadvantage on standardized vocabulary tests for a very large sample of well-matched CWS. However, spontaneous language measures of lexical diversity did not distinguish the groups. This relative weakness in CWS may emerge from task differences: CWS are free to encode their own spontaneous utterances but must comply with explicit lexical prompts in standardized testing situations.

Lexical Diversity Measures’ Review And Classification

This paper reviews various lexical diversity (LD) measures and their classification. The authors define the most significant advantages and disadvantages of the measures and investigate the main scopes of LD application. They include measuring LD in the speech of children and people with aphasia, checking progress in learning a foreign language, and investigating different writing styles of certain authors. Results show that the most frequently used measure is the type-token ratio (TTR), which means the ratio of different words (types) to the total number of words (tokens). The most important problem of TTR and other measures based on TTR is that the more tokens a text has, the less is the TTR value. This has led to the development of other measures; some of them are based on a TTR formula, thus, they do not solve the problem and the calculation result is also affected by the text length. In that case, the texts with different length cannot be compared. Another group of measures rests upon the TTR formula supplemented by a principle of sample forming. These measures solve the problem of the TTR partially or completely, though they often require some extra instruments. Fortunately, these instruments are available on the Internet and demand no particular knowledge on their working principle or in programming. Contemporary researchers tend to use independent measures, because texts mostly have different length and the dependent measures cannot give proper results.

Lexical Diversity Versus Lexical Error in the Language Transcripts of Children With Developmental Language Disorder: Different Conclusions About Lexical Ability

Purpose The purpose of this study was to provide preliminary data on differences in lexical diversity and lexical-semantic errors in the language samples of children with developmental language disorder (DLD) and children with typical language development (TLD) of the same age. Method We analyzed word use in the narrative transcripts of children with DLD and TLD (N = 14; M age = 6;8 [years;months]) using standard measures of lexical diversity (number of different words, moving-average type-token ratio) and additional counts of lexical-semantic errors. Results There were no significant differences between the groups in lexical diversity, and all children with DLD scored within the age-appropriate range on diversity relative to a normative sample. The children with DLD, however, produced significantly more lexical errors than their TLD peers. Conclusions The results suggest that caution is warranted when interpreting normal-range lexical diversity scores in children with DLD, as children with DLD may demonstrate functional difficulties with word use that are not captured by lexical diversity measures. A focus on lexical errors holds promise for characterizing lexical-semantic qualities of language transcripts that are not captured by standard measures of diversity. Development of a reliable clinical system for coding and characterizing lexical-semantic errors in language transcripts is warranted.

Psychometric Evaluation of Lexical Diversity Indices in Spanish Narrative Samples From Children With and Without Developmental Language Disorder.

Purpose The purpose of the current study was to examine construct validity evidence for the following 4 lexical diversity measures for use in Spanish narrative samples of children with developmental language disorder and typical language development (TLD): (a) type-token ratio (TTR; Chotlos, 1944 ; Templin, 1957 ), (b) hypergeometric distribution D ( McCarthy & Jarvis, 2010 ), (c) measure of textual lexical diversity (MTLD; McCarthy, 2005 ), and (d) moving-average TTR (MATTR; Covington & McFall, 2010 ). Method A multiple-group, confirmatory factor analytic stepwise procedure was applied to examine factorial invariance in a sample of 435 monolingual Spanish-speaking children (335 with TLD and 100 with specific language impairment). Results MATTR was the strongest indicator of the lexical diversity of a sample and demonstrated measurement invariance across children with TLD and specific language impairment. MTLD scores included some noise at different levels as a function of the length of a sample, especially for short language samples, but differences in relation to MATTR were relatively small. The validity of hypergeometric distribution D and TTR score interpretations was low, as the scores covaried systematically with length, with TTR being the poorest measure of lexical diversity. Conclusion Results support the use of MATTR and MTLD as measures of lexical diversity and should assist clinicians and researchers in the selection of lexical diversity measures to minimize bias in score interpretations when conducting language sample analyses.

Semantic and phonological aspects of lexical retrieval in bilingual aphasia

Semantic and phonological aspects of lexical retrieval in bilingual aphasia

Neuroanatomical structures supporting lexical diversity, sophistication, and phonological word features during discourse

Deficits in lexical retrieval are commonly observed in individuals with post-stroke aphasia. Successful lexical retrieval is related to lexical diversity, lexical sophistication, and phonological word properties; however, the crucial brain regions supporting these different features are not fully understood. We performed MRI-based lesion symptom mapping in 58 individuals with a chronic left hemisphere stroke to assess how regional damage relates to spoken discourse-extracted measures of lexical diversity, lexical sophistication, and phonological word properties. For discourse transcription and word feature analysis, we used the Computerized Language Analysis (CLAN) program, Stanford Core Natural Language Processing, Irvine Phonotactic Online Dictionary, Lexical Complexity Analyzer, and Gramulator. Lesions involving the left posterior insula and supramarginal gyri and inferior fronto-occipital fasciculus were significant predictors of utterances with, on average, lower lexical diversity. Low lexical sophistication was associated with damage to the left pole of the superior temporal gyrus. Production of words with lower phonological complexity (fewer phonemes, higher phonological similarity) was associated with damage to the left supramarginal gyrus. Our findings indicate that discourse-extracted features of lexical retrieval depend on the integrity of specific brain regions involving insular and peri-Sylvian areas. The identified regions provide insight into potentially underlying mechanisms of lexically diverse, sophisticated and phonologically complex words produced during discourse.

The Effects of Task Complexity and L2 Proficiency on L2 Written Performance

Although extensive task-based research has focused on how the manipulation of task complexity affects L2 performance, less attention has been paid to its combined effects with those of L2 proficiency. In this study, 41 Korean learners of English carried out a written task with two levels of task complexity, operationalized as number of elements. Participants were divided into three groups, based on their level of L2 proficiency. Performance was assessed by syntactic complexity, lexical diversity, and accuracy measures. Significant interaction effects between L2 proficiency and task complexity were found on lexical diversity and accuracy measures, especially in the high-proficiency group. Findings are discussed in relation to Robinson’s Cognition Hypothesis and attentional resources available for task performance.

Effects of English-medium instruction on Spanish students’ proficiency and lexical diversity in English

Within higher education, it is often believed that the adoption of English-medium instruction (EMI) will provide domestic students with the language skills that will enable them to be more competitive in their future professional pursuits. However, research into language learning and EMI at the university level is very scarce. This study examined essays by 195 undergraduate students (99 1st-year and 96 3rd-year learners) at a major university in Spain in order to investigate the effect of three years of instruction through the medium of English on their level of proficiency, essay quality and lexical diversity (as measured by the Oxford Placement test, the CEFR writing scale and three measures of lexical diversity). The results showed a significant improvement in the learners’ second language (L2) proficiency and a significant but subtle increase in essay quality ratings but no significant increase in lexical diversity scores. In the same vein as the findings of some of the other studies we discuss, the present findings seem to suggest the need to rethink and re-evaluate the implementation of EMI in contexts like the one examined in this study.

The Vocabulary Richness of Children’s Television in Ireland: A Cross-generational Comparison

This research investigates whether the vocabulary richness of children’s programming has changed over one generation, and therefore compares the programmes offered in 1992 to those offered in 2017. Three hours of programming were sourced, transcribed and coded using the Computerised Language Analysis (CLAN) software (MacWhinney, 1984). CLAN is a language analysis software originally developed for the purpose of analysing child language which allows for the detailed transcription and analysis of linguistic data, including statistical measures of lexical diversity (Pye & MacWhinney, 1994).
 The total words, words per minute, vocabulary diversity, total object, action, attribute and affective-state words as well as the total object, action, attribute and affective-state words spoken in the presence of a referent were calculated and compared for the programming.
 The vocabulary richness of children’s television has decreased over time. The number of words spoken in the presence of referents in the programming has increased over time, with this increase being significant for action and attribute words. This pattern of findings reflects a trend in children’s television towards the production of programmes of reduced lexical complexity which may facilitate children’s word learning.

The applicability of D, MTLD, and MATTR in Mandarin–speaking children

PurposeThe purpose of this study is to evaluate the applicability of D, the Measure of Textual Lexical Diversity (MTLD), and Moving ¬Average Type ¬Token Ratio (MATTR) for measuring lexical diversity of Mandarin-speaking preschoolers. This study examined if D, MTLD, and MATTR can be used to differentiate two different age groups (children age 3 and 4 years) and two language ability groups (typically developing children and children with language delay). MethodSeventy-eight Mandarin-speaking typically developing children and 56 Mandarin-speaking children with language delay participated in this study. The researchers collected, transcribed, and analyzed language samples from these children. ResultsThe findings showed that D and MTLD were sensitive LD measures for assessing the Mandarin-speaking preschoolers. D and MTLD differentiated the two different age groups and language ability groups. The D and MTLD scores of typically developing children were significantly higher than those of children with language delay. Also, 4-year-olds had significantly higher D and MTLD scores than 3-year-olds. MATTR differentiated the two language ability groups but not the two age groups. Possible factors influencing the sensitivity of lexical diversity measures were discussed. ConclusionsThe findings indicated that D and MTLD were sensitive for assessing Mandarin-speaking preschoolers from Taiwan. MATTR can be used to identify children with language delay in this study.

Bilinguals' Sensitivity to Grammatical Gender Cues in Russian: The Role of Cumulative Input, Proficiency, and Dominance.

This paper reports on an experimental study investigating the acquisition of grammatical gender in Russian by heritage speakers living in Norway. The participants are 54 Norwegian-Russian bilingual children (4;0–10;2) as well as 107 Russian monolingual controls (3;0–7;0). Previous research has shown that grammatical gender is problematic for bilingual speakers, especially in cases where gender assignment is opaque (Polinsky, 2008; Schwartz et al., 2015; Rodina and Westergaard, 2017). Furthermore, factors such as proficiency and family type (one or two Russian-speaking parents) have been argued to be important. Interestingly, previous findings differ with respect to the kind of errors children make: restructuring to a two-gender system (masculine–feminine, see Polinsky, 2008) or defaulting to masculine (see Rodina and Westergaard, 2017). It is also not clear to what extent children are sensitive to gender cues or whether certain agreement patterns are simply memorized. To investigate this, we used both existing nouns and nonce words and tested both transparent and opaque gender cues. The results were checked against a number of background factors measuring exposure, proficiency, and dominance. Our findings show that bilingual children are clearly sensitive to morphophonological cues for gender assignment. The most common and robust error pattern for all bilinguals involved overgeneralization to masculine (especially affecting neuter and opaque nouns). At the same time, children from families with two Russian-speaking parents and monolinguals also occasionally overused feminine with vowel-final nouns. The following variables were found to be the most reliable predictors of accuracy on grammatical gender tasks: cumulative length of exposure (CLoE) and consistency of input in Russian, as well as the presence of older siblings, with CLoE to Russian being by far the most robust and important predictor. Furthermore, we show that a lexical diversity measure (number of different words in a Russian narrative) is also correlated significantly with the children’s performance on the gender tasks. At the same time, our results indicate that relative measures of dominance (e.g., the difference in exposure between the two languages or the difference in narrative scores) may be redundant when more robust absolute measures are present (CLoE and lexical diversity in the heritage language).

Day by day, hour by hour: Naturalistic language input to infants.

Measurements of infants' quotidian experiences provide critical information about early development. However, the role of sampling methods in providing these measurements is rarely examined. Here we directly compare language input from hour-long video-recordings and daylong audio-recordings within the same group of 44 infants at 6 and 7 months. We compared 12 measures of language quantity and lexical diversity, talker variability, utterance-type, and object presence, finding moderate correlations across recording-types. However, video-recordings generally featured far denser noun input across these measures compared to the daylong audio-recordings, more akin to 'peak' audio hours (though not as high in talkers and word-types). Although audio-recordings captured ~10 times more awake-time than videos, the noun input in them was only 2-4 times greater. Notably, whether we compared videos to daylong audio-recordings or peak audio times, videos featured relatively fewer declaratives and more questions; furthermore, the most common video-recorded nouns were less consistent across families than the top audio-recording nouns were. Thus, hour-long videos and daylong audio-recordings revealed fairly divergent pictures of the language infants hear and learn from in their daily lives. We suggest that short video-recordings provide a dense and somewhat different sample of infants' language experiences, rather than a typical one, and should be used cautiously for extrapolation about common words, talkers, utterance-types, and contexts at larger timescales. If theories of language development are to be held accountable to 'facts on the ground' from observational data, greater care is needed to unpack the ramifications of sampling methods of early language input.

Sentence Diversity in Early Language Development: Recommendations for Target Selection and Progress Monitoring.

This clinical focus article describes how to assess and when to target diverse, simple sentences as part of early language intervention. The theoretical foundations and clinical motivations for assessing sentence diversity based on unique combinations of subjects and verbs are explained, followed by a description of how to compute the measure. Sentence diversity is then related to familiar developmental measures of lexical diversity, utterance length, and grammatical complexity in a sample of 40 typically developing toddlers at 30 months of age. Descriptive and correlational analyses are used to demonstrate how sentences become more diverse as utterances also become longer and more complex. The ability to produce simple sentences with diverse subject-verb combinations is proposed as a general developmental expectation for toddlers at 30 months of age. All 40 children produced at least 10 different subject-verb combinations in 30 min of parent-toddler conversation. Sentence diversity is also associated with familiar developmental measures. Recommendations are provided for using the measure of sentence diversity to inform treatment planning and monitor progress for young children with language disorders. https://doi.org/10.23641/asha.5895976.