The study was to develop a system based on the probability reasoning of Bayesian Network and OT theory into the Moon unit. This system was composed of On-line Adaptive Diagnostic Test System and Computerized Adaptive Remedial Instruction. The Moon unit was Nature and Life Technology course in Grade four at primary school. After taking the test, the unpracticed competence indicators of students were diagnosed individually, and then correspondent remedial instruction Flash animators were presented to them to learn. This system tried to induce the error types that students made and to validate the effect of the system.
The results were as follows. 1. The stability of execution interface increased up to 96% at Computerised Adaptive Diagnostic Test System. The number of items tested by students in the Computerized Adaptive Diagnostic Test System is 35 averagely. This system can save 10 items averagely, and the test-taking time is also saved simultaneously.
2. After the Adaptive Remedial Instruction, Student’s grades increased twenty. The progress of students is significant.
Therefore, the Online Adaptive Learning System proposed in this study can factually test and remedy students’ abilities individually.
