Human computer interaction (HCI) lies at the crossroads of many scientific areas including artificial intelligence, computer vision, face recognition, motion tracking, etc. In recent years there has been a growing interest in improving all aspects of the interaction between humans and computers. It is argued that to truly achieve effective human-computer intelligent interaction (HCII), there is a need for the computer to be able to interact naturally with the user, similar to the way human-human interaction takes place.Humans interact with each other mainly through speech, but also through body gestures, to emphasize a certain part of the speech and display of emotions. As a consequence, the new interface technologies are steadily driving toward accommodating information exchanges via the natural sensory modes of sight, sound, and touch. In face-to-face exchange, humans employ these communication paths simultaneously and in combination, using one to complement and enhance another. The exchanged information is largely encapsulated in this natural, multimodal format. Typically, conversational interaction bears a central burden in human communication, with vision, gaze, expression, and manual gesture often contributing critically, as well as frequently embellishing attributes such as emotion, mood, attitude, and attentiveness. But the roles of multiple modalities and their interplay remain to be quantified and scientifically understood. What is needed is a science of human-computer communication that establishes a framework for multimodal "language" and "dialog", much like the framework we have evolved for spoken exchange.Another important aspect is the development of Human-Centered Information Systems. The most important issue here is how to achieve synergism between man and machine. The term "Human-Centered" is used to emphasize the fact that although all existing information systems were designed with human users in mind, many of them are far from being user friendly. What can the scientific/engineering community do to effect a change for the better?Information systems are ubiquitous in all human endeavors including scientific, medical, military, transportation, and consumer. Individual users use them for learning, searching for information (including data mining), doing research (including visual computing), and authoring. Multiple users (groups of users, and groups of groups of users) use them for communication and collaboration. And either single or multiple users use them for entertainment. An information system consists of two components: Computer (data/knowledge base, and information processing engine), and humans. It is the intelligent interaction between