The Declaration on Parliamentary Openness calls on parliaments to make information available “in an open and structured format… that can be read and processed by computers, so that parliamentary information can be easily reused and analyzed…” (Provision 35). To illustrate the value of open parliamentary data and potential for sharing and reuse to inform our understanding of complex data and processes, OpeningParliament.org has created the series “What Opening Parliamentary Information Can Tell Us about Our Parliaments.” To contribute, please comment below or contact us.

How has the partisan and ideological makeup of the US Congress changed over time? What events in US history caused Americans to shake up the ideological identity of their Congress and opt for a redirection of their nation’s policies?  An infographic by Randall Munroe, a small chunk of which is displayed above, helps answer these complex questions. The infographic draws on data about the votes of individual members of Congress; where an individual member sits within the ideological spectrum is based on how consistently he/she votes with his/her colleagues. Beginning in 1982, political scientists began the painstaking process of collecting the data, which dates to 1789. The political scientists enabled Randall to develop this insightful image by making the dataset publicly available in an open and structured format and enabling public reuse.