Young children's language and communication skills are crucial for their academic success and overall well-being. Vocabulary size, letter-sound knowledge, and vocalization ability are key predictors of future linguistic proficiency. However, a significant "word gap" exists between children from high and low socioeconomic status (SES) backgrounds, with low-SES children receiving considerably less verbal input. This disparity is evident as early as 18 months and is linked to smaller vocabularies and poorer academic outcomes. This study explores the potential of interactive technologies, specifically tablet-based interventions, to address this issue by fostering vocabulary acquisition and pre-reading skills, especially in resource-constrained environments. While there's concern about excessive screen time, research suggests that high-quality, interactive screen time can be beneficial. This study aims to investigate the causal effects of a brief, interactive tablet-based intervention on linguistic and communicative skills in toddlers and preschoolers.

Existing research indicates a strong correlation between early language development and later academic achievement. Studies highlight the importance of vocabulary size, phonological awareness (letter-sound knowledge), and vocalization as key predictors of future literacy skills. The "word gap" phenomenon, characterized by significant disparities in vocabulary size between high and low SES children, has been extensively documented. This gap stems from differences in the amount of language exposure children receive, with low-SES children receiving significantly less verbal interaction. While the detrimental effects of excessive screen time have been noted, there's growing interest in the potential benefits of high-quality interactive screen experiences. Meta-analyses on the effects of touchscreen technology on young children's learning show a generally positive, albeit moderate effect. However, further research is needed to establish causal links between interactive technology use and improvements in language skills, particularly in the context of carefully designed and implemented interventions.

Two experiments were conducted, one with toddlers (approximately 24 months old, n=101) and one with preschoolers (approximately 42 months old, n=152). A pre-post equivalent group design was employed, with a study group receiving a tablet-based intervention and a control group receiving the intervention after the study period. Participants were matched based on age, sex, and pre-intervention scores on language and communication assessments. The intervention involved a tablet-based game using the fast-mapping paradigm, teaching uncommon word-object associations and letter-sound associations. Preschoolers were also encouraged to vocalize during the game. Pre- and post-intervention assessments included standard measures of language and communication skills (ASQ-3, CDI for toddlers; ASQ-3, TECAL, TEPROSIF for preschoolers). Data analysis involved comparing pre-post gains between the study and control groups, using appropriate parametric and non-parametric tests (t-tests, Wilcoxon tests, ANOVA, and non-parametric longitudinal analyses). Long-term memory for learned associations was also assessed several months after the intervention.

Experiment 1 (toddlers): The intervention resulted in significantly greater gains in the ASQ-3 Communication domain and CDI Adverbs and Verbs subset for the study group compared to the control group. The study group also showed a greater improvement in category change within the Communication domain. While both groups performed similarly in the game, the study group demonstrated superior language and communication skill gains. Experiment 2 (preschoolers): The intervention led to significantly greater gains in the TECAL vocabulary subscale and total scores for the study group compared to the control group. No significant differences were found in category changes between groups. Both groups showed similar game performance. Long-term memory for word-object and letter-sound associations was significantly above chance levels in both age groups, with no significant differences between the study and control groups four to six months post-intervention. Analysis across experiments showed a significant effect of group, with the study groups demonstrating greater overall gains than the control groups. Preschoolers also showed greater overall gains than toddlers. Correlations between game performance and linguistic gains were weak, suggesting the intervention might enhance general-domain cognitive abilities relevant to language development.

The findings support the hypothesis that a brief, tablet-based intervention can positively impact linguistic and communicative abilities in toddlers and preschoolers. The observed gains, while modest, are significant given the relatively short duration of the intervention and the focus on low-frequency words and letter-sounds. The lack of strong correlations between game performance and language gains suggests that the intervention might be improving general cognitive abilities that facilitate language development, such as attention, memory, and symbol use. The improved performance on the word-object tasks compared to letter-sound tasks could be due to children's greater familiarity with objects. The social interaction inherent in the game design, with its contingent feedback and positive reinforcement, likely contributed to its effectiveness. These results have important implications for early childhood education, particularly in low-resource settings, suggesting that carefully designed interactive technologies can provide effective language stimulation.

This study demonstrates the positive impact of a short tablet-based intervention on the language and communication skills of toddlers and preschoolers. The findings highlight the potential of interactive technology to address the word gap and provide valuable language stimulation, especially in resource-limited environments. Future research should investigate the impact of longer interventions, explore the underlying cognitive mechanisms of the observed benefits, and examine the intervention's effectiveness across various SES levels and linguistic contexts.

The study's limitations include the moderate effect sizes observed, the focus on a specific population (low-income families), the lack of in-depth assessment of home environments, and the absence of long-term academic outcome data. The sample sizes, while comparable to previous studies, could also be increased for stronger statistical power. Future research should address these limitations by employing larger, more diverse samples, incorporating detailed home environment assessments, and tracking children's academic progress over extended periods.