The present invention includes method and system for intelligent knowledge diagnosis and tutoring in any knowledge domain. It differs from prior arts with new knowledge model for knowledge presentation and heuristic algorithms. The knowledge model allows the present invention to be applied to curricula in different knowledge domains quickly and cost effectively. The knowledge model and related computational algorithms provide effective and intelligent knowledge diagnosis and tutoring with minimum requirement on assessment content and learning content. It also allows easy curriculum customization and learner initiated learning assistance to meet needs of different teaching and learning styles. The present invention gains better understanding of learner's knowledge status and hence provides more accurate assistance as learner progresses in the curriculum. The present invention can be an add-engine to existing learning management systems working with existing assessment and learning content in any format.