Many libraries collect massive amounts of data, but much of that data sits in a spreadsheet, waiting for mandatory reporting, bragging about services, or other reporting. Meanwhile, public service departments make major decisions based on impressions, anecdotes, and past practice. At UMKC Libraries, librarians have been working toward increased evidence-based decision making, and particularly in public services on making decisions about staffing and services based on data. The presenters discuss best practices for collecting data that can inform decisions, the tools and methods they use at UMKC for data collection and analysis, and several examples of how they used this data to make decisions about proposed changes to staffing and services.