Professor Kerry Lee, Chair Professor of Child Development and President of Yew Chung College of Early Childhood Education delivered a keynote speech at the PECERA-HK 2024-2025 Annual Meeting cum Young Scholars Conference on 11 January 2025. Professor Lee provided a comprehensive exploration of methodologies in studying children’s development, focusing on both the limitations of cross-sectional studies and the opportunities presented by more robust approaches.

He began by critically examining cross-sectional studies that investigate the cognitive and environmental factors influencing children’s development. He argued that these studies are relatively straightforward to design and execute, but they are becoming increasingly difficult to publish—and for good reasons.

By definition, development is a dynamic process that unfolds over time. Cross-sectional studies, which capture data at a single point in time, inherently lack the temporal dimension necessary to explore how children’s growth and development evolve.

This limitation is particularly problematic given that many hypotheses regarding cognitive and environmental correlates are centered on how changes in these factors influence developmental trajectories in the future. Professor Lee underscored that relying on cross-sectional data to test such hypotheses can lead to estimation errors, as demonstrated by simulation studies. Such errors arise primarily due to the failure to account for the dynamic interplay of variables over time.

In the second part of his address, Professor Lee shifted focus to the statistical models that are used for studying developmental changes. He highlighted methodologies, such as growth curve modeling, structural equation modeling (SEM), and latent class analysis, which allow researchers to better capture the complexities of development over time. These models are essential for identifying patterns, making predictions, and understanding how various cognitive and environmental factors interact to shape developmental outcomes. Professor Lee emphasized that these statistical tools provide researchers a much richer framework for testing hypotheses and drawing meaningful conclusions.

Beyond the theoretical aspects, Professor Lee also shared practical insights into running longitudinal studies. Although longitudinal research is often considered the gold standard for studying development, it comes with its own set of challenges. He addressed logistical hurdles, such as participant retention, funding constraints, and the need for meticulous planning to ensure consistent data collection over extended periods. He offered strategies for overcoming these obstacles, including establishing strong participant relationships, leveraging technology for data collection, and designing studies with sufficient flexibility to adapt to unforeseen circumstances.

In his talk, Professor Lee not only highlighted the limitations of cross-sectional studies but also championed the importance of longitudinal research in capturing the true nature of developmental processes. His keynote urged researchers to adopt more rigorous methodologies, consider the value of advanced statistical tools, and navigate the practical challenges of longitudinal studies to advance the field of developmental science.