This study explores the effects of training parents to administer focused stimulation intervention to teach specific target words to their toddlers with expressive vocabulary delays. Twenty-five mothers and their late-talking toddlers were randomly assigned to treatment and delayed-treatment (control) groups. Vocabulary targets were individually selected for each toddler based on the child's phonetic repertoire and parent report of vocabulary development. Following treatment, mothers' language input was slower, less complex, and more focused than mothers in the control group. Concomitantly, their children used more target words in naturalistic probes, used more words in free-play interaction, and were reported to have larger vocabularies overall as measured by parent report. In addition, the treatment had an effect on language development—children in the experimental group used more multiword combinations and early morphemes than children in the control group. The implications of these results are discussed with regard to the role of focused stimulation intervention for children with expressive vocabulary delays.

The results of this study suggest that caregivers' responsiveness in group interactions is highly dependent on the context of the interaction and, to a lesser extent, on the language abilities of the children. Future research is required to determine if inservice training can enhance levels of responsiveness and accelerate language learning in young children in group care.

This exploratory study investigated the outcome of in-service training on language facilitation strategies of child care providers in day care centers. Sixteen caregivers were randomly assigned to experimental and control groups. Caregivers were taught to be responsive to children's initiations, engage children in interactions, model simplified language, and encourage peer interactions. At posttest, the experimental group waited for children to initiate, engaged them in turn-taking, used face to face interaction, and included uninvolved children more frequently than the control group. In turn, children in the experimental group talked more, produced more combinations, and talked to peers more often than the control group. The results support the viability of this training model in early childhood education settings and suggest directions for future research.

This study examined the relationship between variation in maternal language and variation in language development in a group of 12 children with expressive vocabulary delays. Mothers and their children participated in a parent-mediated intervention that adhered to the interactive model of language intervention. This intervention model arises out of social interactionist accounts of language acquisition and maintains that maternal language input has facilitatory effects on child development. The purpose of this study was to examine two compatible explanations for the facilitatory effects of maternal linguistic input in this intervention model: the responsivity hypothesis and the structural hypothesis. The responsivity hypothesis maintains that linguistic input that is semantically contingent on the child’s vocal or verbal utterances, or responsive to the child’s focus, facilitates language learning. The structural hypothesis posits that structural features of maternal language input that are just one step above the child’s abilities promote language learning. The results of this study indicated robust relationships between maternal use of imitation and expansion at Time 1 and measures of child language at Time 2. These results provided support for the effects of responsive language input on the language abilities of this sample of late talkers. These results have implications for social interaction theory and confirm the import of responsive input as viable intervention techniques for young children with expressive vocabulary delays.

Five subtypes of directiveness were examined in the interactions of day care teachers with toddler and preschooler groups. The instructional context (book reading, play dough) yielded significant differences across all five subtypes of directiveness, indicating that these two activities elicited different types of teacher-child discourse. Book reading was characterized by significantly more behavior and response control and less conversation control in comparison with the play-dough activity. Correlations between teachers' directiveness and child language productivity indicated that behavior control and turn-taking control were associated with low levels of productivity, whereas conversation control was associated with the highest levels of productivity. The results of this study confirm that instructional context is an important mediator of teachers' directiveness and suggest that subtypes of directiveness have differential effects on child language output.