What does mean this expression 'top-down approach' in this sentence? Thank you in advance.
This is the sentence,

To attack these difficulties, researchers tried to use the 'top-down approach' using a computer in an attempt to program all the essential rules onto a single disc.

Question

What does mean this expression 'top-down approach' in this sentence? Thank you in advance.
This is the sentence,

To attack these difficulties, researchers tried to use the 'top-down approach' using a computer in an attempt to program all the essential rules onto a single disc.

Answer

The "top-down" approach in this case should have been defined earlier in your text, and so without context, I cannot give a precise answer.

Generally "a top-down approach" is one in which the solution is proposed at the top of an institution e.g. government, and implemented throughout the rest of the institution e.g. lower levels of government and the people.