Public library advocacy helps libraries secure the funding and other support they need to continue providing valuable services to their users. Because advocacy often involves outreach to local decision-makers who are motivated by results, one of the most effective tools for a public library advocate is impact data, or quantitative evidence of the positive benefits that public library services provide to people in their community.
By understanding the important link between advocacy and impact data, and by learning how to effectively gather and measure impact data, you can greatly improve your advocacy efforts.
Understanding Impact Data
Impact data is different from performance data, which measures factors like the number of computers, classes, or services available at public libraries. Instead, impact data focuses on the difference that these factors have made for individuals or communities.
Impact data measures changes in:
- Knowledge and skills
- Attitudes and perceptions
- Behavior
- Quality of life
- Broader social or economic change.
For example, rather than reporting on how many library users attended a computer literacy class, impact data looks at how many library users used their new skills to get a job.
Get started with this primer on measuring the impact of public libraries: Download 
Impact Data and Advocacy
Measuring impact allows public libraries to show how they contribute to measurable results like job skills developed, education attained, employment found, money saved, and livelihoods improved. When you incorporate library impact data into advocacy messages, you can:
- Demonstrate the value that the public library provides to the community in terms that your audience will understand
- Appeal to the priorities and interests of the decision-makers you want to reach
- Make the case for continued or increased funding
Hear how public libraries around the world have successfully used impact data: Download
Measuring Impact
Use the following steps to collect impact data and incorporate it into your advocacy efforts:
- Determine what to measure by identifying information that will be important to policy- and decision-makers.
- Create a survey that will collect information for the indicators you have chosen.
- Administer the survey to a random sample of public library visitors (ideally at regular intervals – e.g., once a year – in order to measure changes over time).
- Analyze and synthesize the data that is collected.
- Examine the data to develop key messages and insights that will resonate with key audiences.
- Use the data about the impact of library services to persuade policy- and decision-makers.
Read the methodology for collecting and measuring impact data: Download
Survey Tools and Additional Information
There are many existing resources for public library staff interested in learning more about impact data, conducting surveys, or measuring results. They include:
- The Impact Survey: This online survey tool allows public library staff to easily survey patrons about technological services at their libraries, and how these services improve their lives. Impact Survey Website
- The Advocacy Training Curriculum: The advocacy training curriculum has a session called “Using Library Perception Information and Impact Data” where you can get more information on how impact data can be used in library advocacy. Session 6
- How to Learn More: This document connects you to other online resources available to public libraries, from useful articles and webinars to survey templates and tools. Download