REFERENCES
- Horstmann, H. M., & Levine, S. P. (1990). Modeling of user perform-ance with computer access and augmentative communication systems for handicapped people. Augmentative and Alternative Communication, 6, 231–241.
- Horstmann, H. M., & Levine, S. P. (1992). Modeling AAC user performance: Response to Newell, Arnott, and Waller (1992). Augmentative and Alternative Communication, 8, 92–97.
- Newell, A. F., Arnott, J. L., & Waller, A. (1992). On the validity of user-modeling in AAC: Comments on Horstmann and Levine (1990). Augmentative and Alternative Communication, 8, 89–92.
- Newell, A. (1972). Problem solving. Englewood Cliffs, NJ: Prentice-Hall.