The document discusses open data in clinical research and how it relates to big data. It notes that open data means data that can be analyzed and used by anyone through linkages and evidence-based applications. The document outlines key principles for open data, including clarity of use, data quality, and managing data reuse. It describes benefits like crowd-sourcing analysis, data linkage insights, and improved data quality. Finally, it summarizes that for clinical research, open data is a way to securely analyze and apply insights from big data.