Creating an expert system’s knowledge base is the heart of knowledge engineering. This description covers steps 5 of the process at a high level.
Proto-branch creation
Following random content creation, the knowledge engineering team can move next to the creation of prototype branches through the domain. These branches will form the basis for the eventual creation of a logic-based decision tree through the domain.
Purpose of proto-branches
These proto-branches will serve a few purposes, including:
- laying down the foundational logic that will support the creation of multiple new branches in the decision tree(s) capturing expert knowledge in the domain
- providing an early indication of the knowledge engineering work, which will help with project planning and estimating
- continuing the gradual orientation to knowledge engineering for subject matter experts and the rest of the team
Proto-branches don’t have to reach the stage of full completion. Once the main knowledge engineering work begins, the proto-branches are likely to undergo many significant alterations.
Build on the random content generation work
The content generated from the earlier random content generation step will be a starting point for the proto-branches.
Knowledge engineers should work with subject matter experts to select 1 or 2 problems to prototype.
Identify a starting point
The expert system’s knowledge base will work on the basis of logic-based rules in the form of a decision tree. The proto-branches need to start at the base of the tree.
The starting point should represent the most general diagnosis or categorization of the subject matter in the domain.
Create the branches’ structure and flow
The proto-branches will generally reflect the following pattern (which will be covered in more depth later):
- Diagnosis: 2-5 rules with multiple options or branches in the decision tree to diagnose the problem or narrow the subject matter in the domain
- Information resources: as the problem is diagnosed, small, specific bits of information can be delivered to the user
- Action, tools or self-help: at least one action-oriented resource to enable self-resolution or problem management for each branch before it terminates
- Triage: if it’s appropriate for the domain, diagnosis questions can filter out users with particular problems or needs that require special attention and transition some cases to other service providers
- Streaming: determine the appropriate service or process to direct users to at the conclusion of their interaction with the expert system
Convert to questions and answers
After the basic structure is created, the knowledge engineers can convert it to a question and answer format. A question will be placed at each branch just before it splits. Answers will take users down specific branches.
In the language of expert systems, the question invites the user to provide input to the system. The user’s input causes a specific rule to fire, moving the user through the knowledge base along the branch that corresponds to the answer.
Mock-up informational resources
To further boost realism, informational resources within the proto-branches can be mocked up to express the general idea of the information they contain in the context of the new question and answer format of the content.
These resources don’t have to be complete at this point. They will likely undergo several revisions later.
Create proto-branch endings
Any endings to the proto-branches should be roughly mocked up to serve as the termination points for the expert system.
Load the knowledge into the system
An optional step for proto-branch creation is to load the content into the expert system. Loading it offers a chance for the knowledge engineers and subject matter experts to try the content in the system – giving them a better assessment of the flow of the finished product.