Before moving into the senior manager role, Dan worked with the Web-Based Intermediaries (WBI) group, which successfully launched the research vehicle WBI as a component of IBM's WebSphere web-technology creation / development environment.  He is also affiliated with "PlanetBlue," a large cross-lab project that's developing systems solutions and technology for the ubiquitous and pervasive support of knowledge workers.

Prior to his engagement at IBM, Dan managed the User Experience Research group at Xerox Palo Alto Research Center.  Returning to PARC after a nearly 5 year stint at Apple, he spent 9 months working on the design of a complete user experience for a new class of information appliance.  The group designed and implemented Madcap, a highly interactive browser for large, richly coordinated media collections.

Until September of 1997, Dan was the Director of the Knowledge Management Technologies laboratory within Apple's Advanced Technology Group (ATG).  In this capacity, he coordinated the research efforts of five areas (Intelligent Systems, Spoken Language, User Experience, Interaction Design, and Information Technology) to provide an amalgamating, integrative direction to the research as a whole.   Before KMT, he managed Apple's  User Experience Research group, which studied issues of sensemaking, cognitive modelling of analysis tasks, synchronous and asynchronous collaboration, shared awareness of individual state,  joint work coordination, and knowledge-based use of complex, heterogenous information.

Prior to joining  Apple in 1993, Dan was a Member of the Research Staff at the Xerox Palo Alto Research Center (PARC) in the User Interface Research group studying uses of information visualization techniques.  Before that, from 1984 through 1991 he led the "Instructional Design Environment" project (with both Richard Burton and Tom Moran) to develop a practical computer-aided design and analysis system for use in ill-structured design tasks. In addition to his work at PARC, he is an adjunct lecturer on the Engineering and Computer Science (Computer Science) faculty of the University of Santa Clara, and teaches special topics classes in Artificial Intelligence at Stanford University.