The IQ Exchange For Intelligence Systems, AI, Expert System, Virtual Reality
The Brain
The Brain Functions
Brain-Like Computers
The Brain & DNA
Intelligence Quotes
Personal Intelligence
Personal Intelligence
Personal IQ
Business Intelligence
Business Intelligence
Data Warehouses
Expert Systems
Expert Systems
Artificial Intelligence [AI]
Aviation Expert Systems
Virtual Reality
Augmented Reality
Virtual Reality


Expert System Interfaces

There are two interfaces to an expert system:

  1. The user interface
  2. The procedure interface

These are both important functions in the information collection process.

The User Interface

The user interacts with the system through a user interface which may use menus, natural language or any other style of interaction.

The function of the expert system user interface is to present questions and information to the operator and supply the operator's responses to the inference engine.

In such cross referenced applications, communication between the user interface and the inference engine is performed through the use of a User Interface Control Block (UICB) which is passed between the two.

  1. Values entered by the user must be received and interpreted by the user interface.
  2. Responses can restricted to a set of possible answers, or not, as appropriate.
  3. The user interface checks all responses to insure that they are of the correct data type.
  4. Any responses that are restricted to a defined set of answers are compared against all answers.
  5. Whenever the user enters an illegal answer, the user interface informs the user that his answer was invalid and prompts him to correct it.


Procedure Node Interface

The function of the procedure node interface is to receive information from the procedures coordinator and create the appropriate procedure call. It must be:

  • Able to call a procedure and receive information from that procedure.
  • Permitted to invoke any procedure allowed on its host system. This makes the expert system useful in a much wider class of knowledge domains than if it had no external access or only limited external access.
  • In machine diagnostics, particularly self-diagnostic applications, it is not possible to conclude the current state of "health" of a machine without some information. The expert system must be able to receive this information directly from the machine.
  • Manage node functions, for example:

    Able to ask specific question to obtain information from the operator, to create an evidence node.

    A leaf that is an external node indicates that data will be used which was obtained from a procedure call.

    A reference node functions to refer to another tree or subtree.

    A tree may also contain intermediate or minor nodes between the goal node and the leaf node. An intermediate node can represent logical operations like And or Or.

The inference logic has two functions.

  1. It selects a tree to trace and then it traces that tree.
  2. Traces the tree, depth-first then left to right.


Tracing refers to the action the system takes as it traverses the tree, asking classes [questions], calling procedures, and calculating confidences.

The selection of a tree depends on the ordering of the trees [the order in which they appear in the rulebase]. This order can be changed by assigning an evidence node an attribute 'initial'.

Once the values for all evidence nodes which have been assigned an "initial" attribute have been obtained, the rules are ordered so that the most likely to succeed is evaluated first. The trees are constantly being updated as a selected tree is being traced and as such can be re-ordered.


User Profiling

The type of information solicited by the system from the user using questions or classes can in some systems be tailored to the level of knowledge of the user.

In many applications, a group of prospective users are defined, the knowledge level can be estimated, and questions presented at a level which corresponds generally to the average user.

In other applications, knowledge of the specific domain of the expert system might vary considerably among the group of prospective users.


Self Diagnostic Modes

Using an expert system in a self-diagnostic mode on a personal computer is often done to assist the operator to diagnose the cause of a fault or error in either the hardware or software.

Many expert systems gather knowledge from experts - but in some cases, such as a computer, the knowledge is resident in the machine itself, and is best sourced from there. When the accuracy of the data supplied by an operator is potentially low, the expert system can not effectively process it to a meaningful conclusion. In this case, the dialog is between the machine and the diagnostic program.

The information is obtained through a process of inductive or deductive reasoning.

NEXT: Further Resources


Back To Top