The phrase "considerable research" means a significant amount of investigation, study, or exploration that has been done on a particular topic or subject. Full definition
You should also do considerable research on several housing markets even if some of the housing markets aren't where you wanted to live in the first place. (mortgagecalculator.biz)
The template has been developed after considerable research, and it supports editing too! (template.net)
What the brain is doing when an individual is not focused on the outside world has become the focus of considerable research in recent years. (sciencedaily.com)