How to narrow down your topic for research?

Having a variety of sources (pooled) may assist in determinating which research topics are significant and which are not. Additionally, chosing more detailed words may assist in narrowing down, such as: nitrogen instead of nutrient soils.. Based on narrowing down the keywords jn research, the topic may become narrower as well. Following this procedure we may scale the keywords to similar phrases and form a complete research topic that's been narrowed down