Why do we need to limit the scope of the study

Explanation:

Lack of available and/or reliable data -- a lack of data or of reliable data will likely require you to limit the scope of your analysis, the size of your sample, or it can be a significant obstacle in finding a trend and a meaningful relationship.

what group of people depend on what yoy are talking i will still you once you tell me what group of people you are talking about : )

i think i know what group you are talking about so the brahmins

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.