Most Web sites are designed to be viewed by audiences inside an organization and are often not visible to the larger World Wide Web. Although these intranet sites employ the same technology as sites designed for the larger Web audience, their design and content should reflect the different motivations of intranet users.
External sites are usually aimed at capturing an audience. The overall goal is to maximize contact time, drawing readers deeper into the site and rewarding their curiosity with interesting or entertaining information. One assumption that governs Web design is that readers may have little motivation to stay and must be constantly enticed and rewarded with rich graphics or compelling information to linger within the site.
Successful intranet sites assemble useful information, organize it into logical systems, and deliver the information efficiently. You don't want intranet users lingering over their Web browsers, either in frustration at not being able to find what they are seeking or in idle "surfing." Allow employees and students to get exactly what they need quickly and then move on.