A markup language for building a data warehouse for educational peer-assessment research

Peer assessment has proved to be a useful technique in all levels of education. The process of giving and receiving comments can encourage critical thinking and help students learn both from reviewing and being reviewed. Peer assessment generates a large volume of data, especially if done online. Online peer-assessment systems are designed differently and use different schema for their data, which complicates the work of comparing different designs. For example, some systems are based on ranking - reviewers rank the artifacts they are asked to assess, while other systems use rating - reviewers assess a single artifact at a time and score it on various criteria. Comparing these two types of systems, e.g. on rating accuracy, or usefulness of formative feedback, can be challenging because researchers need to learn the design and terminology of each system before analyzing the data. We introduce a Peer-Review Markup Language to provide a common definition of terminology across multiple systems. We are using this markup language to build a data warehouse for data from different systems. We discuss issues raised during this process and our approach to solving them.