Question 6912 – UGC NET CS 2015 Dec – paper-3

Forward Chaining: Forward chaining starts with the available data and uses inference rules to extract more data until a conclusion is reached.
It is also known as data driven inference technique.
It is bottom up reasoning.
It is a breadth first search.
For Example: “If it is raining then i will bring the umbrella”. Here “it is raining” is a available data from which more data is extracted and a conclusion “i will bring the umbrella” is drived.
Backward Chaining: Backward chaining is an inference method described colloquially as working backward from the goal.
It is also known as goal driven inference technique.
Here we starts from a goal and apply inference rules to get some data.
It is top down reasoning.
It is a depth first search.
For Example: “If it is raining then i will bring the umbrella”. Here our conclusion is “i will bring the umbrella”. Now If I am bringing an umbrella then it can be stated that it is raining that is why I am bringing the umbrella. So here “ It is raining” is the data obtained from goal . Hence it was derived in a backward direction so it is the process of backward chaining.