Cookies

A cookie is a small data file that certain Web sites write to your hard drive when you visit them. A cookie file can contain information such as a user ID that the site uses to track the pages you've visited. But the only personal information a cookie can contain is information you supply yourself. A cookie can't read data off your hard disk or read cookie files created by other sites.

The National Academies search engine uses cookies to create a unique, random user ID which is used to create a logon session. Sessions last for ten minutes unless the user logs off manually. Cookies are NOT required to visit any other area of the National Academies web site. Logon sessions allow users to review their query results.

If you've set your browser to warn you before accepting cookies, you will receive the warning message with each cookie. If you've turned cookies off in your browers, the query page of the search engine will prompt you to turn it on.