The Association Between Parental Mean Length of Utterance and Language Outcomes in Children With Disabilities: A Correlational Meta-Analysis

The impact of social-environmental factors on IQ in syndromic intellectual developmental disabilities

Despite having the same underlying genetic etiology, individuals with the same syndromic form of intellectual developmental disability (IDD) show a large degree of interindividual differences in cognition and IQ. Research indicates that up to 80% of the variation in IQ scores among individuals with syndromic IDDs is attributable to nongenetic effects, including social-environmental factors. In this narrative review, we summarize evidence of the influence that factors related to economic stability (focused on due to its prevalence in existing literature) have on IQ in individuals with syndromic IDDs. We also highlight the pathways through which economic stability is hypothesized to impact cognitive development and drive individual differences in IQ among individuals with syndromic IDDs. We also identify broader social-environmental factors (e.g., social determinants of health) that warrant consideration in future research, but that have not yet been explored in syndromic IDDs. We conclude by making recommendations to address the urgent need for further research into other salient factors associated with heterogeneity in IQ. These recommendations ultimately may shape individual- and community-level interventions and may inform systems-level public policy efforts to promote the cognitive development of and improve the lived experiences of individuals with syndromic IDDs.

The Association Between Mother's Descriptive Language and Children with Autism's Conversational Repair: A Moderated Mediation Analysis

This study tested the role of children with autism spectrum disorder (ASD)'s conversational expansion in mediating between mothers' descriptive language and children with ASD's conversational repair, and whether this mediation was moderated by the relative complexity of mother-child language. Videos of forty children with ASD engaging in various activities with their mothers were transcribed into language samples and then coded. Mediation analyses indicated that conversational expansion mediated the association between descriptive language and conversational repair. Moderated mediation analysis further indicated that the relative complexity of mother-child language moderated the relationship between descriptive language and conversational expansion, creating a conditional indirect effect. Although preliminary, the results of this study provide parents and practitioners with a new idea of language intervention strategies.

Efficacy of a Self-Directed Video-Based Caregiver-Implemented Language Programme

INTRODUCTION

Caregiver-implemented language programmes are effective for alleviating early language difficulties. This study examined the efficacy of a self-directed video-based caregiver-implement language programme in Chinese families.

METHOD

This study consisted of two stages. In stage 1, 31 caregiver-child dyads (typically developing children) completed the training programme (group 1) in the form of six video-based training modules. In stage 2, 28 caregiver-child dyads (children with language difficulties) receiving active speech therapy were randomly assigned to the training (group 2) and control arms (group 3). Group 2 received the same training as group 1 in addition to their regular therapy while group 3 was kept as status quo. Caregivers completed a quiz on their knowledge of language facilitation techniques (LFTs) and submitted caregiver-child interaction videos at the start and end of the training. Outcome measures included programme completion rate, quiz scores, and use of LFTs and children's communication skills in the videos. A pre-post design and a between-group design were adopted in the stage 1 and 2 studies, respectively.

RESULTS

A completion rate of about 60% in both stages was noted. Significantly higher post-training knowledge scores were found in groups 1 and 2. General but nonsignificant growth in use of parallel talk and gesture, and significant gains in children's vocalization in the training arm were observed.

CONCLUSION

The self-directed video-based training programme would be useful in imparting information to caregivers. However, the modest improvements in the use of LFTs suggested direct coaching appeared to still play a significant role in enhancing the actual implementation of LFTs. Further investigation on a larger scale is required to evaluate the effectiveness of the training programme for promoting the wider use of this mode as a preventive measure.

Whose Gestures are More Predictive of Expressive Language Abilities among Chinese-Speaking Children with Autism? A Comparison of Caregivers' and Children's Gestures

In spite of the close relationship between gestures and expressive language, little research has examined the roles of the parents' and children's gestures in the development of expressive language abilities in autistic children. Previous findings are also inconclusive. In the present study, we coded the gestures produced by the parents and their autistic children in parent-child interactions and compared the influence of their gestures on the children's expressive language abilities (N = 35; M = 4;10). Autistic children's deictic gestures positively predicted their Mean Length Utterance (MLU), word types, and word tokens whereas parents' deictic gesture inputs negatively predicted MLU and word types. The findings shed light on the importance of the gestures made by autistic children, which may trigger parents' gesture-to-word translation.

Caregiver linguistic alignment to autistic and typically developing children: A natural language processing approach illuminates the interactive components of language development

BACKGROUND

Language development is a highly interactive activity. However, most research on linguistic environment has focused on the quantity and complexity of linguistic input to children, with current models showing that complexity facilitates language in both typically developing (TD) and autistic children.

AIMS

After reviewing existing work on caregiver engagement of children's utterances, we aim to operationalize such engagement with automated measures of linguistic alignment, thereby providing scalable tools to assess caregivers' active reuse of their children's language. By assessing the presence of alignment, its sensitivity to the child's individual differences and how well it predicts language development beyond current models across the two groups, we showcase the usefulness of the approach and provide initial empirical foundations for further conceptual and empirical investigations.

METHODS

We measure lexical, syntactic and semantic types of caregiver alignment in a longitudinal corpus involving 32 adult-autistic child and 35 adult-TD child dyads, with children between 2 and 5 years of age. We assess the extent to which caregivers repeat their children's words, syntax, and semantics, and whether these repetitions predict language development beyond more standard predictors.

RESULTS

Caregivers tend to re-use their child's language in a way that is related to the child's individual, primarily linguistic, differences. Caregivers' alignment provides unique information improving our ability to predict future language development in both typical and autistic children.

CONCLUSIONS

We provide evidence that language development also relies on interactive conversational processes, previously understudied. We share carefully detailed methods, and open-source scripts so as to systematically extend our approach to new contexts and languages.

Speech-Language Pathologists' Endorsement of Speech, Language, and Literacy Myths Reveals Persistent Research-Practice Gap

PURPOSE

We explore the extent to which speech-language pathologists (SLPs) are operating under assumptions about speech, language, and literacy that are not supported by evidence or are contradicted by evidence.

METHOD

SLPs (N = 106) marked the degree to which they endorsed or rejected four true and 11 myth (i.e., false) statements on a visual analog scale via an online survey. We analyzed the degree to which participants agreed or disagreed with these statements related to speech, language, and literacy development and impairment.

RESULTS

Based on results of one-sample t tests, participants as a group correctly rejected seven myth statements and correctly endorsed three true statements. Participants as a group provided equivocal responses to the remaining four myth statements and one true statement. Scores for each statement spanned all or nearly all of the possible range. Even when participants overall showed relatively strong disagreement with a particular myth statement, at least a few participants endorsed the myth statement.

CONCLUSIONS

The findings indicate areas of relative strength for SLPs' knowledge of current evidence for augmentative and alternative communication, bilingualism, and language input that supports language development. Identified areas of relative weakness include knowledge of the expected grammatical and speech production skills of children with typical development and the influence of ear infections in childhood on language impairment. Additional research is needed to evaluate efforts to enhance SLPs' knowledge and use of evidence-based practices.

The influence of child-based factors and parental inputs on expressive language abilities in children with autism spectrum disorder

LAY ABSTRACT

Language impairment is one of the early signs of Autism Spectrum Disorder (ASD) that alerts parents to take their children for early diagnosis and intervention. Little is known about how children's autism traits, IQ, initial language abilities and parental inputs influence their language abilities. In addition, only a few studies have compared the relative influence of these factors. The present study addressed these issues by examining the structural language in parent-child spontaneous interactions. Forty-two Cantonese (Chinese)-speaking autistic children aged four to eight were recruited. Their expressive language skills grew rapidly more than 9 months, but their development trajectories varied. Initial expressive language ability is the only significant predictor of child language outcomes and language growth trajectories. In contrast, nonverbal cognition, autism traits, and parents' input do not affect language outcomes in children with ASD. Therefore, early language intervention is crucial for autistic children at all severity and IQ levels.

Antenatal depression and maternal infant directed speech during the first postnatal year

BACKGROUND

Antenatal depression is emerging as a potential risk factor for lower maternal sensitivity during postnatal mother-infant interactions. The present study investigated the relationship between both antenatal and postnatal depression and features of infant directed speech, a key indicator of maternal sensitivity during the first postnatal year.

METHODS

Pregnant women with either a clinical diagnosis of Major Depressive disorder (MDD; n = 20) or a history of MDD (n = 26) and a control group (n = 34) were recruited to the study and followed up at two, six and twelve months postpartum. A free-play mother-infant interaction was recorded at each time-point and the lexical and syntactic complexity of the mothers' speech was measured from the transcript.

RESULTS

No significant group differences were observed at either two, six or twelve months. However, mediation analyses indicated that antenatal depression was indirectly associated with maternal syntactic complexity at two and twelve months through concurrent maternal depression scores.

LIMITATIONS

The findings of this study are limited by its small sample size. The sample also comprised predominantly well-resourced women which limits the generalisability of the findings to wider or less advantaged populations.

CONCLUSIONS

This study contributes to the emerging evidence base concerning the impact of antenatal depression and postnatal depression on early mother-infant interactive behaviour, specifically infant-directed speech. These findings further highlight the importance of identifying women with antenatal depression in order to support them to engage in therapeutic interventions at the earliest possible opportunity.

A Systematic Literature Review of Autism Research on Caregiver Talk

Describing how caregivers' talk to their autistic children, and how their talk may influence social and language outcomes, has important implications for developmental theory and intervention research. In this systematic literature review, we examine 294 caregiver talk variables extracted from 65 studies, provide a narrative overview of research findings, and link measurement approaches to various theories of language development. The majority of variables included only talk directed to children (90%), and specified the speech act being performed (57%). More than one-third of variables measured talk that was responsive to children's attention, activities, or communication (38%), and slightly less than a third measured variables that elicited children's communication or engagement. Semantic aspects of talk were specified in 41% of variables, structural features were measured in 20% of variables, and suprasegmental features were measured in only 1% of variables. Talk quantity (without reference to other aspects of talk) was measured in 8% of variables. We found strong support that talk related to children's attention is implicated in autistic children's language development, but this construct has been measured inconsistently in terms of semantic, structural, and functional features. There is also evidence for bi-directional relationships between caregiver's talk and autistic children's development on a variety of semantic and structural variables. LAY SUMMARY: In our review, we found many differences in how researchers measured caregiver's talk, but also some promising leads. Researchers should continue examining caregiver talk related to children's focus of attention to clarify how this type of language contributes to autistic children's development. We also found interesting research on how children influence caregiver's talk, and encourage researchers to continue to study how this occurs.

Development of Neural Structure and Function in Autism Spectrum Disorder: Potential Implications for Learning Language

Purpose Neurodevelopmental processes that begin during gestation and continue throughout childhood typically support language development. Understanding these processes can help us to understand the disruptions to language that occur in neurodevelopmental conditions, such as autism spectrum disorder (ASD). Method For this tutorial, we conducted a focused literature review on typical postnatal brain development and structural and functional magnetic resonance imaging, diffusion tensor imaging, magnetoencephalography, and electroencephalography studies of the neurodevelopmental differences that occur in ASD. We then integrated this knowledge with the literature on evidence-based speech-language intervention practices for autistic children. Results In ASD, structural differences include altered patterns of cortical growth and myelination. Functional differences occur at all brain levels, from lateralization of cortical functions to the rhythmic activations of single neurons. Neuronal oscillations, in particular, could help explain disrupted language development by elucidating the timing differences that contribute to altered functional connectivity, complex information processing, and speech parsing. Findings related to implicit statistical learning, explicit task learning, multisensory integration, and reinforcement in ASD are also discussed. Conclusions Consideration of the neural differences in autistic children provides additional scientific support for current recommended language intervention practices. Recommendations consistent with these neurological findings include the use of short, simple utterances; repetition of syntactic structures using varied vocabulary; pause time; visual supports; and individualized sensory modifications.

Speech-Language Pathologists' Ratings of Telegraphic Versus Grammatical Utterances: A Survey Study

Purpose It is common for speech-language pathologists (SLPs) to simplify their utterances when talking to children with language delays, but there is disagreement about whether simplified utterances should be grammatical (e.g., Daddy is running, See the cookie?) or telegraphic (e.g., Daddy running, See cookie?). This study examined the extent to which SLPs reported grammatical versus telegraphic utterances to sound like something they would say and investigated whether results differed based on SLPs' perspectives about the usefulness of telegraphic input. Method Ninety-three practicing SLPs completed an online survey. SLPs rated the extent to which a list of telegraphic and grammatical utterances sounded like something they would say to a child with a language delay who is prelinguistic or at the one- or two-word stages of spoken language development. Results SLPs who did not view telegraphic input as useful or felt neutral about this issue rated grammatical utterances to sound significantly more like something they would say than telegraphic utterances. However, findings differed for SLPs who viewed telegraphic input as useful. There was no significant difference in the extent to which these SLPs reported grammatical versus telegraphic utterances to sound like something they would say. Conclusions As incorrect language models, telegraphic utterances are counterexamples to the grammatical structure of English that may make it more difficult for learners to detect regularities in the language input they hear. Unless empirical evidence emerges in support of telegraphic input, it may be beneficial to maximize grammatical input provided to children with language delays.

Brief Report: Learning Language Through Overhearing in Children with ASD

We explored whether children with autism spectrum disorder (ASD) learn new nouns from overheard speech. Thirteen children (4-5 years) with ASD participated in an Addressed condition, in which they were directly taught a novel label (e.g., toma) for one of three novel objects, and an Overheard condition, in which the objects and label were presented in a conversation between two adults. In both conditions, children were then asked to identify the labeled object (e.g., "find the toma"). Children selected the target novel object at rates above chance in the Addressed condition, and of critical importance, they also did so in the Overheard condition. This suggests that, like TD children, children with ASD may learn from language that is not directed to them.

Reciprocal Influences Between Parent Input and Child Language Skills in Dyads Involving High- and Low-Risk Infants for Autism Spectrum Disorder

We examined the language input of parents of infants at high and low familial risk for autism spectrum disorder (ASD) and investigated reciprocal associations between parent input and child language skills in the first 2 years of life. Parent-infant dyads (high-risk: n = 53; low-risk: n = 33), 19 of whom included an infant later diagnosed with ASD, were videotaped during free play interactions at 12, 18, and 24 months. Measures of parent input were derived from parent-child interactions. Children's language skills were assessed using the Mullen Scales of Early Learning at 12, 18, and 24 months. Results suggested that (a) parents of high- and low-risk infants produced similar word tokens, word types, and proportions of contingent verbal responses, but parents of high-risk infants used shorter mean length of utterances (MLU) than parents of low-risk infants at 18 and 24 months; (b) parents' MLU at 18 months was positively associated with their infants' language at the subsequent visit after 6 months, regardless of group; and (c) infants' language at 18 months was positively associated with parents' MLU at the subsequent visit after 6 months in the high-risk group only. These findings contribute to our understanding of the mechanisms underlying early language learning of high-risk infants who have an increased risk for language delays and deficits. Autism Res 2020, 13: 1168-1183. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Parents provide an important source of language input to their children. In this study, we looked at parent input to infants at high- and low-risk for autism spectrum disorder and relations between parent input and child language in the first 2 years of life. We found that parents of high- and low-risk infants provided similar quantity and quality of input, except shorter average length of utterances at 18 and 24 months in the high-risk group. Also, there were bidirectional relations between parent input and child language at 18 and 24 months in high-risk pairs, suggesting that parents and children collectively shape the early language environment.

Language nutrition for language health in children with disorders: a scoping review

The quantity and quality of child-directed speech-language nutrition-provided to typically-developing children is associated with language outcomes-language health. Limited information is available about child-directed speech to children at biological risk of language impairments. We conducted a scoping review on caregiver child-directed speech for children with three clinical conditions associated with language impairments-preterm birth, intellectual disability, and autism-addressing three questions: (1) How does child-directed speech to these children differ from speech to typically-developing children? (2) What are the associations between child-directed speech and child language outcomes? (3) How convincing are intervention studies that aim to improve child-directed speech and thereby facilitate children's language development? We identified 635 potential studies and reviewed 57 meeting study criteria. Child-directed speech to children with all conditions was comparable to speech to language-matched children; caregivers were more directive toward children with disorders. Most associations between child-directed speech and outcomes were positive. However, several interventions had minimal effects on child language. Trials with large samples, intensive interventions, and multiple data sources are needed to evaluate child-directed speech as a means to prevent language impairment. Clinicians should counsel caregivers to use high quality child-directed speech and responsive communication styles with children with these conditions.

Twins' and Singletons' Linguistic Environment: A Systematic Review

Background: Among twins, lower linguistic skills emerged when compared with singletons. Considering the association found between parental linguistic input and children's language development, exploring the differences between twins and singletons' linguistic environments could find variables that are potentially associated with the lower linguistic skills of twins.

Aim: The current systematic review aims to analyze and systematize the existing literature focused on the comparison of twins' and singletons' linguistic environments within their first 3 years of life. Methodological issues (i.e., the procedure used to assess the linguistic environment, the coding of the linguistic environment's features, the computational method employed to assess the parental linguistic input, and participant characteristics) and differences found among twins and singletons regarding their linguistic environment (i.e., linguistic input quantity, linguistic input complexity, linguistic features of child-directed speech, parental responsiveness, and directiveness, joint attention, and book reading) were highlighted.

Method: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement was followed. Eligible studies were searched through EBSCO, PubMed, and Web of Science. From this search, 1,347 study results emerged, and 8 studies were included.

Results: To our knowledge, this is the first systematic review focused on the comparison of twins' and singletons' linguistic environments. Differences between the groups were found in all of the included studies. Data against twins were generally identified regarding all the considered linguistic environment's features. However, conflicting results within and between the included studies emerged, mainly according to the computational method employed (i.e., twin moms value, twin direct dyadic value, twin direct dyadic + both value, and input directed toward both children simultaneously).

Conclusion: The disadvantaged linguistic environment of twins is likely due to limited parental resources and demands associated with the management of two children of the same age. However, the limited and conflicting data found did not allow for a firm conclusion to be drawn on the differences in the twins' and singletons' linguistic environments. Further studies on the topic are needed.

Using Telegraphic Input With Children With Language Delays: A Survey of Speech-Language Pathologists' Practices and Perspectives

Purpose Speech-language pathologists (SLPs) often simplify their language input when talking to young children with language delays, but there is some controversy regarding whether simplified input should be telegraphic (e.g., Ball under, Doggie go, More toy) or grammatical (e.g., The ball went under; Go, Doggie! More toys). The purpose of this study was to evaluate SLPs' practices and perspectives on using telegraphic input when working with children with language delays at the prelinguistic, one-word, or two-word stages of spoken language development. Method Practicing SLPs were recruited from a university-sponsored professional development conference focused on current best practices in speech-language pathology. Respondents completed an online survey that included questions about their own practices, as well as their overall perspectives on the usefulness of simplifying language input in different ways. Results The vast majority of SLPs (82%) reported using telegraphic input. SLPs reported using telegraphic input more frequently when prompting for verbal imitations than when describing play or providing a directive/request. Surprisingly, only 30% of SLPs who reported using telegraphic input felt that it was useful. SLPs reported that receptive language is the most important child characteristic to consider when deciding what kind of language input to provide. Conclusions These findings suggest the need for more purposeful clinical decision making in the context of providing simplified language input. In addition, in-depth, qualitative studies are needed to characterize the complex interactions among beliefs, experiences, practices, and perspectives pertaining to simplified language input.

Hearing me hearing you: Reciprocal effects between child and parent language in autism and typical development

Language development in typically developing children (TD) has traditionally been investigated in relation to environmental factors, while language in children with autism spectrum disorder (ASD) has primarily been related to child-based factors. We employ a longitudinal corpus of 32 preschoolers with ASD and 35 linguistically matched TD peers recorded over 6 visits (ranging between 2 and 5 years of age) to investigate the relative importance of child-based and environmental factors in language development for both populations. We also investigate the reciprocal interaction between children's response to parents' input, and parents' response to children's production. We report six major findings. (1) Children's production of word types, tokens, and MLU increased across visits, and were predicted by their Expressive Language (EL) (positively) and diagnosis (negatively) from Visit 1. (2) Parents' production also increased across visits, and was predicted by their child's nonverbal cognition (positively) and diagnosis (negatively) from Visit 1. (3) At all visits and across groups, children and parents matched each other in lexical and syntactic production; (4) Parents who produced longer MLUs during a given visit had children who produced more word types and tokens, and had longer MLUs, at the subsequent visit. (5) When both child EL at Visit 1 and parent MLU were included in the model, both contributed significantly to future child language; however, EL accounted for a greater proportion of the variance. (6) Finally, children's speech significantly predicted parent speech at the next visit. Taken together, these results draw more attention to the importance of child-based factors in the early language development of TD children, and to the importance of parental language factors in the early language development of children with ASD.

Prevalence of Publication Bias Tests in Speech, Language, and Hearing Research

PURPOSE

The purpose of this research note is to systematically document the extent that researchers who publish in American Speech-Language-Hearing Association (ASHA) journals search for and include unpublished literature in their meta-analyses and test for publication bias.

METHOD

This research note searched all ASHA peer-reviewed journals for published meta-analyses and reviewed all qualifying articles for characteristics related to the acknowledgment and assessment of publication bias.

RESULTS

Of meta-analyses published in ASHA journals, 75% discuss publication in some form; however, less than 50% test for publication bias. Further, only 38% (n = 11) interpreted the findings of these tests.

CONCLUSION

Findings reveal that more attention is needed to the presence and impact of publication bias. This research note concludes with 5 recommendations for addressing publication bias.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.7268648.

Vocalization patterns in young children with Down syndrome: Utilizing the language environment analysis (LENA) to inform behavioral phenotypes

Children with Down syndrome (DS) are at higher risk for both delayed expressive language and poor speech intelligibility. The current study utilized the quantitative automated language environment analysis (LENA) to depict mother and child vocalizations and conversational patterns in the home of 43 children with DS, chronologically aged 24-64 months. Children with DS displayed fewer utterances than typically developing children; however, there was wide variability. Furthermore, children with DS did not show increased vocalization counts across their chronological ages. In contrast to previous findings, this study found that the mothers of children with DS had a reduced number of vocalizations. However, the vocalizations increased with age in comparison to mothers of typically developing children. Implications for targeted interventions that facilitate learning opportunities in bidirectional contexts for children with DS and their parents are discussed, with particular attention to quantify behavioral phenotypes utilizing a novel expressive language assessment tool.

Contribution of parenting to complex syntax development in preschool children with developmental delays or typical development

BACKGROUND

Despite studies of how parent-child interactions relate to early child language development, few have examined the continued contribution of parenting to more complex language skills through the preschool years. The current study explored how positive and negative parenting behaviours relate to growth in complex syntax learning from child age 3 to age 4 years, for children with typical development or developmental delays (DDs).

METHODS

Participants were children with or without DD (N = 60) participating in a longitudinal study of development. Parent-child interactions were transcribed and coded for parenting domains and child language. Multiple regression analyses were used to identify the contribution of parenting to complex syntax growth in children with typical development or DD.

RESULTS

Analyses supported a final model, F(9,50) = 11.90, P < .001, including a significant three-way interaction between positive parenting behaviours, negative parenting behaviours and child delay status. This model explained 68.16% of the variance in children's complex syntax at age 4. Simple two-way interactions indicated differing effects of parenting variables for children with or without DD.

CONCLUSIONS

Results have implications for understanding of complex syntax acquisition in young children, as well as implications for interventions.

Social Support, Well-being, and Quality of Life Among Individuals on the Autism Spectrum

Social support plays a critical role in the quality of life (adaptive functioning and subjective well-being) of individuals on the autism spectrum across the lifespan.

More Than “Try This at Home”—Including Parents in Early Intervention

Current state and federal recommendations encourage the delivery of early intervention services in a child's natural environment with typical communication partners (Individuals With Disabilities Education Act [IDEA], 2004). As such, speech-language pathologists (SLPs) often provide intervention services in homes and work closely with parents. However, only 30% of SLPs have early intervention expertise (ASHA, 2014) and 68% of SLPs report low-levels of competence in working with infants and toddlers (Campbell, Chiarello, Wilcox, & Milbourne, 2009). This may be due to the fact that the majority of graduate programs (60%) provide little or no training in early intervention (Bruder & Dunst, 2005). Working in early intervention is a challenging albeit rewarding task for even the most seasoned therapist. Given that the largest percentage of children served under part C of IDEA are children with language delays (Hebbeler et al., 2007), it is essential that SLPs working in early intervention implement effective strategies for both parents and children. The purpose of this paper is to: (a) explain why including parents in intervention is important; (b) discuss ways of including parents in early intervention; (c) examine strategies used to teach parents; (d) describe a method for teaching parents; (e) compare methods of measuring parent progress; and (f) propose future directions for research.