Nancy L. Green

 Systems Scientist,
Human-Computer Interaction Institute,
 School of Computer Science,
Carnegie Mellon University

 Address:   HCI Institute, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
Email:    Telephone: (412) 268-3084 Fax: (412) 268-1266

Research Interests

 My current research interests are in human-computer interaction and natural language processing, including

Application areas of this research include computer interfaces, exploratory data analysis, virtual reality and intelligent tutoring systems, automatic generation of documentation, assistive technologies, and computer-supported cooperative work.

Current Activities

 I am a member (9/96 to present) of the Visualization and Intelligent Interfaces Group in the Robotics Institute at CMU. One of our projects is to develop an experimental system, AutoBrief, that can automatically generate presentations in text and information graphics (bar charts, maps, etc.) from databases. (The graphics are generated by the SAGE automatic graphic design system.) Our current testbed application is to integrate AutoBrief with a mixed-initiative scheduling system (DITOPS ) in the domain of transportation scheduling. My main contributions to AutoBrief have been the development of a knowledge representation scheme to serve both text and information graphics (IGW9, CVIR98), and designing and implementing a text microplanner, which plans how content is to be expressed in text. Research areas which I am currently addressing are media selection and coordination (e.g., What content should be expressed in text as opposed to graphics? How can text facilitate comprehension of a complex graphic? How should text about the user's problem-solving domain be integrated with text about the graphic?), multimedia argumentation strategies  to support user tasks ( AAAI98, Draft97), and user manipulation of generated text as an interface device. In addition, I am advising a student at CMU's Language and Technologies Institute; her Ph.D. research is on mixed-initiative interfaces to information systems.

Previous Research

 As a Postdoctoral Research Fellow in the Computer Science Department at CMU (10/94 to 8/96), I was a member of the NL-Soar project. NL-Soar was implemented in the Soar computational model of the human cognitive architecture. NL-Soar's goal was to develop real-time natural language capabilities enabling human students to communicate with intelligent artificial agents in a pilot training system. I implemented NL-Soar's discourse capabilities, using Soar to create a unified approach to discourse planning/learning and plan recognition (SSS98, AAAI96). In addition to its practical goal, the research is a step towards modeling cognitive processes in dialogue processing. In the future, I would like to explore the use of cognitive models of dialogue processing in the design and evaluation of user interfaces, as well as applying machine learning to discourse processing.  I would also like to continue to develop  conversational interface agents.

For my dissertation (Computer Science), I developed a computational model for generating and interpreting indirect answers to yes-no questions. Frequently occurring in human-human dialogue, indirect answers are responses consisting of relevant but not explicitly requested information from which the listener is licensed to infer the intended answer. In my model (CL99, UDel94, IGW7, ACL94, ACL92), indirect answers are generated by the following domain-independent processes: planning to update the common ground, taking the initiative to provide unrequested but relevant information (UMUAI99, SSS97), and simulating interpretation to identify redundant information in the plan which does not need to be explicitly expressed. Interpretation is modeled as recognition of this underlying plan. Possible future work includes empirical studies and computational modeling of related types of inference in dialogue. Indirect answers are a type of context-sensitive implication in dialogue known as conversational implicatures. In earlier research, I modeled the interpretation of normal state implicature (ACL90), another type of conversational implicature. My masters thesis (Linguistics) was in lexical semantics on an inferential taxonomy of adjective classes (UNC80).

Software Industry Experience

 During graduate school (1987-1994 during summers, holidays, and while writing my dissertation), I worked as a Systems Developer in the AI Group at SAS Institute. Our group developed SAS/ENGLISH, an NL-database interface product enabling end users to query their SQL database in English. I started out by co-designing the grammar formalism for the NL parser, provided linguistics expertise, and wrote NL grammars. My last project was to design and implement a  GUI Browser to enable the user to view the structure of his database and see how it relates to the system's English vocabulary. The Browser's text is automatically generated from the user's underlying database and lexicon.

From 1980-1985 I was a Technical Contributor at Data General, for four years in a  database group that developed a native SQL, and for one year in an AI group. I developed systems software including a query optimizer (Database query code generation and optimization based on the cost of alternate access methods, U.S. Patent Number 04829427 ). I also developed expert system prototypes and evaluated AI tools.

Teaching Experience

  • Current, Co-advisor of CMU Language Technologies Institute Ph.D. student, Yan Qu.
  • Fall 1996 - Spring 1997, Philosophy Department, CMU. Supervised the software component of five Computational Linguistics Masters Projects.
  • Fall 1985 - Summer 1986, Computer Science Department, N.C. State University. Full-time visiting instructor of undergraduate CS courses: Introduction to Computer Science (for majors), Operating Systems (CSC202), and File Organization and Retrieval (CSC431).
  • Also held Teaching Assistantships at University of Pennsylvania (Computer Science), University of Delaware (Computer Science), and University of North Carolina (Linguistics).

  • Graduate Education

  • Ph.D. 1995. Computer Science. University of Delaware. Thesis in natural language processing.
  • M.S. 1987. Computer Science. University of Pennsylvania.
  • M.A. 1980. Linguistics. University of North Carolina at Chapel Hill.

  • Selected Professional Activities

  • Program committee member, NACLA 2000
  • Organizer, Workshop on NL in Intelligent User Interfaces
  • Organizer, Argumentation in Computer Media Interest Group (Pittsburgh)
  • Co-organizer, CHI99 Special Interest Group on Natural Language in Computer-Human Interaction
  • Co-chair, 1998 AAAI Spring Symposium on Applying Machine Learning to Discourse Processing
  • Co-chair, 1996 AAAI Spring Symposium on Computational Implicature
  • Project Consultant,  RAGS: A Reference Architecture for Generation Systems
  • Member, American Association for Artificial Intelligence
  • Member, Association for Computational Linguistics

  • and special interest groups:
  • SIGDIAL (Dialogue Processing),
  • SIGGEN (Natural Language Generation),
  • SIGMEDIA (Multimedia Language Processing)
  • Member, Association for Computing Machinery

  • and special interest groups: Other information
  • Selected Publications
  •  Research interests and background (postscript)
  •  Curriculum Vitae (available on request)