Question

Difference between top down and bottom up parsing ques10

Answer 1

Top down and bottom up are both strategies of information processing and knowledge ordering used in variety of fields including software, humanistic and scientific theories.

In practice they can be seen as a style of thinking, thinking or leadership.

Top down approach is essentially the breaking down of a system to gain insight into it's com-positional sub- system in a reverse engineering fashion.
In a top down approach an overview of the system is formulated, specifying, but not detailing, any first level subsystem.

Each sub system is the refined in yet great detail, sometimes in many additional sub system levels, until the entire specification is reduced to base elements.

A top down model is often specified with the assistance of the ''black box'' which makes it easier to manipulate.

Top down approach starts with the bigger picture, it breaks down from their int smaller segments.

Bottom up approach is the piercing together of the system to give rise to more complex system.

Bottom up processing is a type of information based on income data from the environment to form a perception.

In bottom up approach the individuals base elements of the system are first specified in a  great detail.

These elements are then linked together to form larger sub systems, which then in turn are linked, sometimes in many levels until a complete top level system is formed.




 



 

Answer 2

Explanation:

The parsing occurs from the starting symbol to the input string, in top down parsing. On the other hand, parsing occurs from the input string to the starting symbol, in bottom up parsing.