In January 1994, Jerry Yang and David Filo were Stanford Electrical Engineering graduate students at Stanford University. They started a list of web pages in a campus trailer in February 1994, as a way to keep track of their personal interests on the Internet. The lists were published as a web site named "Jerry's Guide to the World Wide Web", and grew large enough to require categories and subcategories organized in a hierarchy. Before long they were spending more time on their home-brewed lists of favorite links than on their doctoral dissertations.