| With the prevalence of computer applications and the improvement of information technology, the computer and information technology education has become more and more prominent. At present, many kinds of schools begin to give the computer courses and the information technology is becoming important for the on-the-job training. As a result, the information technology is now being faced with new opportunities and challenges. Firstly, the paper reviews the history and the status of the elementary computer education briefly, proposes that the skill training and assessment is one of the most prominent issues and discusses the importance of the construction of "knowledge-skill" two dimension education measurement and assessment system to the existing limitation of the teaching assessment. Secondly, the paper introduces the theory of skill training, makes a systemic summarize of the problem-solving theory, the operation decision theory and the process model of the problem-solving based on a detailed survey of literature and establishes the foundation of the latter system design and development. Thirdly, the paper makes a deep research in Learning from example and learning by doing, two modes of the skill training and proposes the elementary principles in constructing learning environment in support of "learning by doing". The focus of the paper is the fourth part introducing the design theory and implementation all around. The iTutor is a new paradigm of ITS(Intelligent Tutoring System) software in which an extended architecture is adopted. The main characteristics of iTutor are the embedment of related learning support in interactive learning environment, the integration of teaching assessment into the problem solving process and the embodiment of learner-centered theory. Lastly, the paper discusses some classic application pattern of iTutor and makes a primary evaluation of the effect. |