XIANGEN HU - It was really fruitful for the PDA period 2001-2002. As originally planned, I was going to conduct three lines of study during the PDA. 1) Continue the study of General Processing Tree (GPT) models, 2) Explore issues related to distant learning, and 3) Working on Federal grants on intelligent tutoring. Next, I will briefly report the above three area of research during the PDA. 

General Processing Tree Models:

This is a line of research I have been working on for over 10 years. During PDA, I have been working on a few papers.  

            1.      Directed Forgetting (with Dr. William Marks): A research project continued from previous studies. We have reported in numerous conferences.

            2.      Empirical Bayes Method for GPT models (with Dr. William Batchelder): A Mathematical/Statistical study of GPT models. This study explores the possibility of using GPT model to handle individual differences.

            3.      GPT Models and Log-linear Models: This study tries to examine the relations between GPT models and log-linear models. 

            4.      GPT with non-binary parameters: This is a direct extension of original GPT model (was based on binary branch) to arbitrary cases.

            5.      Recursive GPT Models (with Dr. George Karabatsos): This is a study tries to use GPT model to approximate categorical models with other functional forms.

            6.      Response Biases for the Models of Source Monitoring (with Dr. William Marks and Lun Mo): This is the mathematical analysis of the experiments in the directed forgetting study.


Explore issues related to distant learning:

During the PDA, I have been consulting for a local high tech company (Thoughtware Technologies, Inc) and University of Memphis on a contract from IDA (institute for Defense Analysis) and NAWCTSD (Naval Air Warfare Center Training System Division) (total of $1000,000).  The contract was to produce a Human Regulatory Affairs Advisor (HURAA). HURAA is an interactive, web-based information delivery and retrieval system that is designed to help users learn the U.S. federal policies and regulations that pertain to using human subjects in research. I have been the chief computer architect. Here is a list of activities attended related to this project: (for details on plugfest, see http://www.adlnet.org


            1.      Plugfest 4: May 30-June 1, 2001, ADL Co-Lab in Alexandria, VA

            2.      Plugfest 5: November 26-29, 2001, Orange County Convention Center in Orlando, FL.

            3.      Plugfest 6: July 30 - August 01, 2002, Defense Acquisition University Fort Belvoir, Virginia

            4.      Academic ADL Co-Lab Partner Meeting: August 13, Madison, WI  (see http://www.academiccolab.org/events/index.html for detail) 

In addition to the presentations and demonstrations in the above conferences, there are other conference presentations: 

            1.      Craig, S.D., Gholson, B., Susarla, S., Hu, X., Graesser, A.C., & Toth, J. (April, 2001).  The Human Use Regulatory Affairs Advisor: A Web-based Information Retrieval System with a user-friendly interface design.  Paper presented at Webnet, the World Conference on the WWW and the Internet.  Orlando, FL. 

            2.      Person, N.K., Gholson, B., Craig, S., Hu, X., Stewart, C., & Graesser, A.C. (June, 2001).  HURA Advisor: A web-based intelligent agent who manages mixed initiative dialog to optimize information retrieval.  Paper presented at the IEEE International Conference on Communications. Helsinki, Finland. 

            3.      Graesser, A.C., Hu, X., & Person, N.K. (August, 2001).  Teaching with the help of talking heads.  Symposium paper presented at the IEEE International Conference on Advanced Learning Technologies.  Madison, WI.

            4.      Ventura, M., Person, N., Jackson, T., Graesser, A., Hu, X., & Toth, J. (January, 2002).  Evaluating learning outcomes in an interactive web-based learning system.   Paper presented at the Winter Text, Discourse, and Cognition conference. Jackson Hole, WY.

            5.      Graesser, A.C., Hu, X., Person, N.K., Stewart, C., Toth, J., Jackson, G.T., Susarla, S., Ventura, M.  (June 2002).  Learning about the ethical treatment of human subjects in experiments on a web facility with a conversational agent and ITS components.  Paper presented at the Intelligent Tutoring Systems 2002 conference, Biarritz, France.

            6.      Graesser, A.C., Hu, X., Olde, B.A., Ventura, M., Olney, A., Lowerse, M., Franceschetti, D.R., Person, N.K. (August, 2002).  Implementing latent semantic analysis in learning environments with conversational agents and tutorial dialog.  Paper presented at the meetings of the 24th Annual Conference of the Cognitive Science Society.   Washington, D.C.

            7.      Graesser, A.C., Hu, X., Person, N., Jackson, G.T., & Toth, J. (October, 2002).  Modules and information retrieval facilities of the Human Use Regulatory Affairs Advisor (HURAA). Paper presented at the meetings of E-Learning 2002.   Montreal, Canada.

            8.   Hu, X., Mathews, E., Graesser, A.C., & Susarla, S. (October, 2002).  EBOOKE.EXE: A Desktop Authoring Tool for HURAA.  Paper presented at the meetings of E-Learning 2002.   Montreal, Canada.


Intelligent tutoring research:

Part of my PDA activity was to work on several Federal and ONR grants awarded to the University of Memphis (Dr. Graesser, PI).  I have been Co-PI for the grants listed below:


            1.      National Science Foundation, Developing AutoTutor for computer literacy and physics, 2001-2004, $1,274,075. 

            2.      Institute for Defense Analysis and ONR NAWCTSD, A Web Site on Institutional Review Boards and the Ethical Use of Human Subjects, 2000-2001, $950,000 ($750,000 through Thoughtware Corporation and $200,000 through U. of Memphis).

            3.      Institute for Defense Analysis, A Web Site on Institutional Review Boards and the Ethical Use of Human Subjects, 2000-2001, $980,000 (through Thoughtware Corporation).

            4.      Office of Naval Research, Why2K: A tutor that teaches mental models using natural language dialogs, 2000-2005, $1,168,700 (other PI is Kurt van Lehn at University of Pittsburgh).


Here is a list of conference publications: 

            1.      Graesser, A.C., Hu, X., Susarla, S., Harter, D., Person, N., Louwerse, M., Olde, B., & the TRG (2001).  AutoTutor: An intelligent tutor and conversational tutoring scaffold. Papers from the Workshop on "Tutorial Dialog Systems" at the Artificial Intelligence in Education 2001 Conference  (pp.47-49).  San Antonio, TX.

            2.      Graesser, A.C., Person, N., & Hu, X. Improving comprehension through discourse processes. New Directions in Teaching and Learning. 


I am pleased that I have been exposed to two new research areas, namely, distant learning and intelligent tutoring and actively participated in several research projects and produced several conference presentations and publications. It has been a very good start for me to continue studies in these two areas. Currently, I have started a few very interesting new research projects in these two areas.  

It would be even better if I could spend more time on my GPT studies. Although I have a few papers in good shape, they still need some time to finish.  It only visited one campus during the PDA. That was the Huazhing Normal University in China (a sister university of UM). I gave an invited address to the faculty members in the Psychology department. We discussed future research collaborations, but it will only happen later (beyond the PDA period).