Measuring Political Deliberation: A Discourse Quality Index

In this paper, we develop a discourse quality index (DQI) that serves as a quantitative measure of discourse in deliberation. The DQI is rooted in Habermas' discourse ethics and provides an accurate representation of the most important principles underlying deliberation. At the same time, the DQI can be shown to be a reliable measurement instrument due to its focus on observable behavior and its detailed coding instructions. We illustrate the DQI for a parliamentary debate in the British House of Commons. We show that the DQI yields reliable data and we discuss how these data could be used in subsequent analysis. We conclude by discussing some limitations of the DQI and by identifying some areas in which it could prove useful.