Knowledge Engineering

Knowledge Elicitation is the process of acquiring knowledge about a specific domain. A conceptual model of the domain knowledge is created at the end of the knowledge elicitation process. It is one of the most important and a crucial task of the development of an expert system since it directly has an impact on the overall quality of the system. Knowledge elicitation is also often viewed as the bottleneck in the development of expert systems or knowledge based systems. It is difficult and time consuming activity.

The knowledge is elicited chiefly from experts in the field and data/ information available from published literature. There are various known knowledge elicitation techniques available. The choice of technique to be used in the knowledge elicitation process depends on the nature of the situation within which the knowledge is elicited, the domain knowledge and availability of experts.

The knowledge elicitation process gets tricky as the vast amount of information is often kept inside the heads of domain experts. This makes the entire process complicated as the domain experts may not be willing to disclose the information, due to worries of being sidelined or becoming less important or getting redundant. In certain domains, the domain experts may not even be aware of the tacit knowledge and implicit conceptual models they come to use over many years of experience.

Some of the techniques used in the knowledge elicitation process are as follows:

• Documentation Analysis: It is used for orientation and preparation. Documentation is perhaps the most common source of information, as it is often readily available. It helps knowledge engineers to conceptualize unfamiliar content and identify critical concepts in the domain. Documentation should not be the solitary source of information, but it normally supplements other sources of information.


• Interviews: Interviews are the oldest and most common tool used for data collection. An interview can be structured or unstructured. Unstructured interviews normally carried out at the early stages of the knowledge elicitation/ modelling process. The structured interviews help to refine the knowledge acquired


• Observation: There are two types of observation techniques, obtrusive and unobtrusive observation. In unobtrusive observation, the observer does not interact with the expert in action. The intention is to observe how a task is being performed usually, without disturbing or interfering in any way. The advantage with unobtrusive observation is that the person will carry out the tasks in a typical manner without any interference. Unobtrusive observation may not always be suitable as certain tasks require interaction to understand the reasoning behind certain steps in the process. In obtrusive observation, the observer gets the person to verbalize his thoughts as the task is being performed.


• Questionnaires


• Protocol analysis


• Laddering


• Repertory Grid Technique


• Card Sorting


• Three Card Trick


• Twenty Questions Technique


• Concept maps and Process maps