EDUCBA Logo

EDUCBA

MENUMENU
  • Explore
    • EDUCBA Pro
    • PRO Bundles
    • Featured Skills
    • New & Trending
    • Fresh Entries
    • Finance
    • Data Science
    • Programming and Dev
    • Excel
    • Marketing
    • HR
    • PDP
    • VFX and Design
    • Project Management
    • Exam Prep
    • All Courses
  • Blog
  • Enterprise
  • Free Courses
  • Log in
  • Sign Up
Home Data Science Data Science Tutorials Head to Head Differences Tutorial Forward Chaining vs Backward Chaining
 

Forward Chaining vs Backward Chaining

Priya Pedamkar
Article byPriya Pedamkar

Updated March 23, 2023

Forward-Chaining-vs-Backward-Chaining

 

 

Difference Between Forward Chaining and Backward Chaining

Forward Chaining vs Backward Chaining is two important strategies in the field of Artificial Intelligence. Its origin lies in the Expert System Domain of AI. One of the most prominent research domains of AI, Expert System was introduced to emulate the decision-making ability of human experts. It has 3 components:

Watch our Demo Courses and Videos

Valuation, Hadoop, Excel, Mobile Apps, Web Development & many more.

  • Knowledge Base: To Store domain-specific and high-quality knowledge.
  • Inference Engine: Use the knowledge from Knowledgebase to arrive at a decision.
  • User Interface: Provides Interaction between the user of the ES and the expert system.

Forward and Backward chaining is the strategies used by the Inference Engine in making the deductions.

Forward Chaining

 Forward Chaining the Inference Engine goes through all the facts, conditions, and derivations before deducing the outcome i.e. it starts with a set of rules to perform a chain of operations to conclude the final decision. This Strategy is used to get the conclusion by manipulating the knowledge from the knowledge base.

Forward Chaining

This strategy is used to answer the question “WHAT CAN HAPPEN NEXT ?”

Properties:

  • Since it moves from top to bottom it’s called a top-down approach.
  • It makes a conclusion by making deductions from data and moving from initial state to the goal state.

Backward Chaining

In this, the inference system knows the final decision, it tries to figure out the conditions that would have resulted in that decision. It is mostly used in finding the cause of a problem.

Knowledge Base

This strategy is used to answer the question “WHY THIS HAPPEN?”

Properties:

  • In this, the goals are broken into sub-goals to prove a fact.
  • It’s a goal-driven approach
  • It used the depth-first strategy for proof.

Head to Head Comparison between the Forward Chaining and Backward Chaining (Infographics)

Below is the top 9 Comparison between the Forward Chaining vs Backward Chaining:

Forward Chaining vs Backward Chaining info

Key Differences Between the Forward Chaining and Backward Chaining

Let us discuss some of the major key differences:

  • Forward chaining is used to deduce the conclusion by taking the facts and move in forward direction by applying the inference rule to get more data, till the time it reaches the goal while in backward chaining it takes the goal and moves backward by using the inference rule to determine the fact which could be the reason for the goal.
  • Forward chaining uses the breadth-first strategy to deduce conclusion while backward chaining uses the depth-first strategy to get the facts.
  • Due to the reason of taking the facts and deducing the result forward chaining is termed as bottom-up approach while backward chaining is also known as a top-down approach.
  • Forward chaining is used to get the goal from data hence it is called a data-driven inference technique while the Backward chaining is used to get the data from the goal it is called goal-driven inference techniques.
  • Forward chaining will search all the possible ways for getting the goal while Backward chaining avoids unnecessary paths.
  • Since Forward Chaining checks all rules it is slow, whereas backward chaining is fast as checks only required rules.
  • Forward chaining can be used in the share market to detect the price of shares using the available data while Backward chaining can be used to know the reason for a cause like cancer.
  • Forward chaining is used in tasks like planning, monitoring, interpretations and control application while backward chaining is used in debugging and diagnostic tasks.
  • Now you might be having a clear understanding of these two strategies of Inference System and how they are related to the Expert System. Look at the figure below to understand their relation:

Expert system

  • Expert and Knowledge Base Engineer creates the Knowledgebase of Expert System, which is then used by the strategies of Inference system to deduce the result in case of forward chaining using the facts and rule available In the knowledge base or getting the reason for the goal by taking the input as a goal from the user and fact and rules from the knowledge base.

Forward Chaining vs Backward Chaining Comparison Table

The table below summarizes the comparisons:

Basis of comparison Forward Chaining Backward Chaining
Question Type Expert System uses this strategy to answer, “What can happen next ?” Expert System uses this strategy to answer, “Why this happen ?”
Approach Follows Bottom-Up approach Follows Top-Down Approach
Type of Strategy It applies the Breadth-First Strategy It applies the Depth-First Strategy
Technique Forward chaining is a data-driven technique It is a goal-driven technique.
Goal Its goal is to get a conclusion. Its goal is to get the possible facts
Operational Direction Forward direction, i.e. it goes from fact to result Backward direction, i.e. it goes from result to facts.
Number of Conclusions It can generate an infinite number of possible conclusions It generates a finite number of possible conclusions
Application It used in monitoring, planning, interpretation and control applications. It is used in prescription, debugging and diagnostics applications.
Speed Slow as it has to use all the rules Fast as it has to use only a few rules.

Conclusion

In this article, we have seen differences between the Forward Chaining vs Backward Chaining with their key differences. I hope you will find this article helpful.

Recommended Articles

This has been a guide to the difference between the Forward Chaining vs Backward Chaining. Here we also discuss the Forward Chaining vs Backward Chaining key differences with infographics, and comparison table. You may also have a look at the following articles to learn more –

  1. Artificial Intelligence Problems
  2. Artificial Intelligence Technology
  3. Pareto Chart in Tableau
  4. Break vs Continue
  5. Guide to Backward Chaining

Primary Sidebar

Footer

Follow us!
  • EDUCBA FacebookEDUCBA TwitterEDUCBA LinkedINEDUCBA Instagram
  • EDUCBA YoutubeEDUCBA CourseraEDUCBA Udemy
APPS
EDUCBA Android AppEDUCBA iOS App
Blog
  • Blog
  • Free Tutorials
  • About us
  • Contact us
  • Log in
Courses
  • Enterprise Solutions
  • Free Courses
  • Explore Programs
  • All Courses
  • All in One Bundles
  • Sign up
Email
  • [email protected]

ISO 10004:2018 & ISO 9001:2015 Certified

© 2025 - EDUCBA. ALL RIGHTS RESERVED. THE CERTIFICATION NAMES ARE THE TRADEMARKS OF THEIR RESPECTIVE OWNERS.

EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you
Loading . . .
Quiz
Question:

Answer:

Quiz Result
Total QuestionsCorrect AnswersWrong AnswersPercentage

Explore 1000+ varieties of Mock tests View more

EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you
EDUCBA
Free Data Science Course

Hadoop, Data Science, Statistics & others

By continuing above step, you agree to our Terms of Use and Privacy Policy.
*Please provide your correct email id. Login details for this Free course will be emailed to you
EDUCBA

*Please provide your correct email id. Login details for this Free course will be emailed to you

EDUCBA Login

Forgot Password?

🚀 Limited Time Offer! - ENROLL NOW