Developing A Data Visualization Guideline For A District Attorney’s Office

• In Event: Visualizations and Platforms Facilitating Public Safety

Abstract

This paper talks about the office’s effort to standardize data visualization styles and promote scientific visualization choices. Data visualizations, including tables, charts and maps play pivotal roles in the communications between the office and its stakeholders. However, visualizations by district attorney’s offices nationwide often face issues such as unclear chart types, confusing designs, and poor default color palettes. Consequentially, these visuals are often confusing to readers despite containing useful data. To address them, I relied on current data visualization literature and drafted a Data Visualization Guideline that dissects what makes a data visualization effective, common pitfalls, and considerations for how to best communicate data visually., The Guideline emphasizes both theories and practical advice using prior work product and successful examples. The document starts by talking about the most fundamental question – what data visualization means, then moves to fundamental principles and theories, and finishes by discussing various chart types and their pros and cons. Finally, the Guideline is accompanied by a R ggplot coding guide and functions to standardize table and chart styles. Taken together, the Guideline helps create effective and impact data visualizations while adhering to best practices.

Authors

• Juncheng Liu, Philadelphia District Attorney's Office

• Yasmin Ayala-Johnson, Philadelphia District Attorney's Office

• Sebastian Hoyos-Torres, Philadelphia District Attorney's Office

• Wes Weaver, Philadelphia District Attorney's Office

• Charles J. Arayata, Philadelphia District Attorney's Office