1. A method of helping a user form a structured diagram from an unstructured information source, wherein at least one artifact is formed in the structured diagram to represent at least one information element included in the unstructured information source, the information element being the objects or the interactive relations among the objects involved in the unstructured information source, the method comprising the steps of: receiving a search item which is inputted by the user and represents an information element; searching for the contents related to the information elements represented by the search item in the unstructured information source based on the search item inputted by the user; and for each information element, creating a linkage between the corresponding artifact formed in the structured diagram and the position of the related content searched in the unstructured information source.