The four parts of an expert system
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which list names all four parts of an expert system?
2. Which part of an expert system holds the facts about the subject?
3. Which part holds the IF-THEN rules?
4. Which part does the reasoning, matching the user's answers to the rules and facts to reach a conclusion?
5. A doctor types symptoms into a screen and reads the advice that appears. Which part is the doctor using?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1knowledge base | AOUTPUT "Do you have a fever? (Y/N)" | |
| 2inference engine | BThe part of an expert system that stores the facts and data about the subject area, gathered from human experts. | |
| 3The rule base holds IF-THEN rules that link facts to conclusions. | CThe part of an expert system that reasons: it searches the knowledge base and applies the rules to reach a conclusion. | |
| 4The interface is how the user enters answers and sees the conclusion. | DFacts are stored in the knowledge base, not the rule base. The rule base only stores the IF-THEN rules. | |
| 5The rule base stores all the facts about the subject, such as a list of diseases. | EReasoning is done by the inference engine. The interface only handles input from the user and output to the user. | |
| 6The interface decides the conclusion by applying the rules to the facts. | FIF fever = TRUE AND rash = TRUE THEN suggest measles |
C
Definitions
knowledge base, rule base, inference engine, interface
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
The ______________ holds the facts
2.
The _________ stores the IF-THEN rules
3.
The ________________ applies rules to facts
4.
The _________ lets the user ask questions
5.
User <-> interface <-> ________________
<-> knowledge base + rule base
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
parts of an expert system
B
knowledge base: holds rules
C
rule base: holds IF-THEN rules
D
inference engine: reasons
Question 2
A
inference engine: holds facts
B
interface: talks to the user
C
knowledge base: holds facts
D
rule base: holds rules
Question 3
A
USER <-> rule base
B
interface <-> inference engine
C
engine <-> knowledge base
D
engine <-> rule base
Question 4
A
kb = list of facts
B
rb = the user screen
C
ie = reasons using kb and rb
D
ui = talks to the user
Question 5
A
Car fault expert system
B
knowledge base: engine facts
C
rule base: IF-THEN fault rules
D
inference engine: asks user
E
interface: asks the user
Answer Key
The four parts of an expert system
Section A: Quick Questions
Q1
B — Knowledge base, rule base, inference engine, interface
Q2
A — Knowledge base
Q3
A — Rule base
Q4
A — Inference engine
Q5
B — Interface
Section B: Match the Pairs
Q1
knowledge base → The part of an expert system that stores the facts and data about the subject area, gathered from human experts.
Q2
inference engine → The part of an expert system that reasons: it searches the knowledge base and applies the rules to reach a conclusion.
Q3
The rule base holds IF-THEN rules that link facts to conclusions. → IF fever = TRUE AND rash = TRUE THEN suggest measles
Q4
The interface is how the user enters answers and sees the conclusion. → OUTPUT "Do you have a fever? (Y/N)"
Q5
The rule base stores all the facts about the subject, such as a list of diseases. → Facts are stored in the knowledge base, not the rule base. The rule base only stores the IF-THEN rules.
Q6
The interface decides the conclusion by applying the rules to the facts. → Reasoning is done by the inference engine. The interface only handles input from the user and output to the user.
Section C: Definitions
Q1
knowledge base, rule base, inference engine, interface — The four parts of an expert system: the knowledge base holds facts, the rule base holds rules, the inference engine reasons, and the interface talks to the user.Section D: Fill in the Blanks
Q1
The knowledge base holds the factsQ2
The rule base stores the IF-THEN rulesQ3
The inference engine applies rules to factsQ4
The interface lets the user ask questionsQ5
User <-> interface <-> inference engine
<-> knowledge base + rule baseSection E: Spot the Error
Q1
B — The knowledge base holds facts. The rules are held in the rule base, so line 2 should say 'holds facts'.
Q2
A — The inference engine does the reasoning by applying the rules to the facts. Facts are held in the knowledge base, so it should say 'reasons'.
Q3
A — The user only communicates with the interface, never directly with the rule base. Line 1 should be USER <-> interface.
Q4
B — The rule base (rb) holds the IF-THEN rules. The user screen is the interface, so line 2 should be rb = list of IF-THEN rules.
Q5
D — Asking the user questions is the job of the interface. The inference engine reasons using the facts and rules, so line 4 should say 'reasons'.