Studies great and small: convergent approaches to understanding language learning

The ability to learn and remember new words is remarkably variable across individuals. By just 8 years old, a child with good vocabulary knowledge can know over 3000 more words than a child with weaker vocabulary knowledge, and this knowledge gap continues to grow with age. These differences have crucial implications for academic success: vocabulary knowledge is tightly related to literacy development, and predicts performance across the school curriculum. This research aims to understand predictors of these differences in word learning, and how to best support retention of new words in long-term memory.

Scientific studies show that the brain processes the day's memories while we are asleep, helping to strengthen them in long-term memory. Our recent research also showed that children's memory for new words improved over a night's sleep, whereas no such improvements were seen during equivalent time spent awake. Their memory showed continued improvements across the course of a week that were consistently larger than adults' memory improvements, indicating that sleep-based processes may be particularly important during this stage of language development. Indeed, the improvements were most noticeable for words less similar to known English words, suggesting that sleep plays a key role in helping children to learn the vast amounts of new information that they encounter. Importantly, we showed that sleeping soon after learning the new words had long-term benefits for memory that were still apparent 1-to-2 months later, and that children with weaker existing vocabulary knowledge especially benefited from learning new words close to bedtime. These findings have important practical implications for supporting struggling learners, particularly given the common view that important topics should be taught in the morning when children are least tired.

However, sleep studies are resource-intensive, and often study small groups of people in unusual settings - such as spending a night in a sleep lab, or having a researcher visit at home in the evening. Before applying these findings to practice, we need to first extend the evidence beyond the lab: do sleep and these associated factors similarly support day-to-day vocabulary development? The proposed fellowship seeks to build bridges between research and practice in two ways: first by improving the accessibility of current research findings within and beyond academia, and second by testing theories of language learning in data sourced from a popular app. In practice, this includes four primary goals to:
1) Ensure high-quality scientific publications from the present research findings, and accessible summaries that can be shared widely with educational practitioners and the general public.
2) Develop my research practices in ways that enhance transparency and openness of the research process, ensuring high-quality future research that can be widely accessed by others.
3) Advance my data skills for analysing "big data" sourced from real-world learning settings (e.g., online platforms, apps).
4) Assess whether sleep similarly benefits memory for new words in real-world learning settings, establishing foundations for future research into better understanding long-term retention of newly learned words.

The proposed fellowship activities will support the broader communication of recent research into the benefits of sleep for long-term memory of new words, and the potential for capitalising upon these benefits to support children who have weaker vocabulary. Importantly, the fellowship will establish foundations for future research into the applicability of these findings for day-to-day learning from a language-learning app, bridging an important gap between vocabulary research and practice.