A service of the U.S. National Library of Medicine 
National Institutes of Health
The American Customer Satisfaction Index (ACSI) Survey
The National Library of Medicine (NLM) is committed to listening to its users and making positive changes to MedlinePlus and MedlinePlus en español. NLM participates in the American Customer Satisfaction Index (ACSI) to measure online user satisfaction.
The ACSI measures users' expectations and perceptions by asking standard questions about site content, navigation, and look and feel. Other questions ask about user demographics, their reasons for visiting the sites, and how they use the health information provided by NLM.
Random MedlinePlus and MedlinePlus en español users receive a pop-up invitation to take the ACSI survey. Users are not required to complete the survey. The survey does not collect or track any information that could identify a specific user.
The sites use sampling rates and a survey cookie to minimize the number of times we ask users to take the survey. The cookie is never used for tracking users' queries or navigation through the sites.
The ACSI survey generates a user satisfaction score based on users' answers to questions on expectations and experience with the site. To find out more about the ACSI, go to www.theacsi.org.