Background: Public health officials often remind all of us that one of the best ways to prevent the spread of germs and keep from getting sick is washing our hands often, and especially after using the bathroom. In order to see if people were washing their hands when signs reminding them to do so were posted, the Minnesota Department of Health decided to do a study, at the State Fair. They went to three big events: a car show in 2003, the State Fair in 2003, and the State Fair in 2004, and observed how many people were washing their hands in the bathrooms.

The graph shows “Average observed hand washing percentages among adult males and females at the Back-to-the fifties car show (1), the 2003 Minnesota state fair (2), and the 2004 Minnesota state fair (3). All observations were carried out in the same two male and two female restrooms.”

Data Source: Minnesota Department of Health,