Explanation facility

Another essential component, different from classical software, of the interaction module is the explanation facility subsystem. The simplest provision is the... 

This, of course, is a very important part of the program. We are developing it on an as-needed basis in response to feedback from users. In particular, we still have not implemented a complete explanation facility. The user interface currently provides online help and a menu based selection of valid responses whenever applicable. 

Justifications for the expert system s recommendations need to be clear and specific. Explanation facilities - such as the why and how queries often found in expert systems - often consist of replaying the logic used by the system to arrive at a conclusion. While this is sufficient for some applications, others require more in-depth justification including causal relationships and assumptions made. Design of the explanation facility must be tied to design of the user interface of the system. 

The ESES expert system provides an explanation facility which justifies the recommendations given to the user (this is the HOW feature, also frequently referred to as the WHY feature in expert system literature). A comprehensive report of the session can be printed for future reference which includes the recommendations given, HOW explanations, a profile of the problem described by the... 

Overview. The CORA expert system has gone through two major phases in its development. The first-phase deliverable was a prototype system. The knowledge bases and explanation facility were written using the Production Rule Language (PRL) of Insight 2+. Additional user interface and reporting capabilities were developed in dBASE III+ and Nantucket Clipper. 

Explanation facility The part of an expert system s user interface which describes how the program reached a particular conclusion. This ability is a key advantage to expert systems, and is an important part of end-user acceptance of the system. 

In order to convert an expert system to an intelligent tutoring system, the expert system must be able to explain its answers. This explanation facility has been added to the PIRExS program by means of amendments to the rules and by addition of disk files that contain all the rules expressed in natural language (English). 

Usually an explanation facility is considered to be an essential part of an expert system. As the basic problem of WOOLY is very complex, this aspect had to be an integral part of the system. Therefore, special care was given to combine every result with the relevant information about the reasons why it was achieved. In most cases this simply means that all the necessary background information appears on the... 

Library of X-Ray Crystal Compounds Abstracted Knowledge of X-Ray Data 3-D Graphical Interface Problem Analyser and Decomposer Analogy Finder Analogy (Similarity) Evaluator Model Assembler Explanation Facility Conformational Analysis Module... 

A general rule-based expert system consists of six components knowledge base, knowledge acquisition facility, database, inference engine, explanation facility and user interface. A functional integration of these components is shown in Fig. 2.1. The functions of these components are described on the next page. 

Inference engine This component carries out reasoning processes whereby the expert system reaches a solution, and links rules in the knowledge base with facts in the database. An inference engine decides which rules are satisfied, prioritizes them and executes those of the highest priority. Explanation facility It enables a user to understand how the expert system arrives at its conclusions. Keeping track of the fired rules, the component presents a trace of reasoning that leads to a certain conclusion. 

Figure 1 The modular structure of an expert system separates the reasoning process (the inference engine) from the specific domain information (the knowledge base) comprising both rules and data. The explanation facility provides a means of tracing the reasoning scheme during or after an analysis.

In addition to the knowledge base and inference engine, an expert system should include an explanatory interface. Its purpose, as its name suggests, is to provide the developer or user with an account of the reasoning strategy employed. Important reasons for a system having an efficient and effective explanation facility are... 

The interface with the user is an important and significant part of an expert system. An expert system s task is not necessarily complete when a question is answered or a problem solved the system must be capable of explaining its reasoning and display how conclusions are attained. The importance of this explanation facility should not be underestimated. A user may be a novice in the domain in which the system operates, and it can have, and manipulate, knowledge outside of the competence of the user. For a user to trust and confidently act on the decisions and results proposed by an expert system its operations and strategies must be transparent. 

A well-developed explanation facility and a good user interface provides expert systems with a valuable role for training and instructing novice users of the analytical technique. 

The author of this review has written a more recent paper on a methodology for assessing the general benefits of ESs in the workplace In this paper, a simple three-level model of benefits is proposed feature benefits, task benefits, and role benefits. This model is said to illustrate how technological features like expert knowledge and explanation facilities can contribute to the eventual success or failure of a system. 

---