"Painstaking research" refers to the careful and thorough investigation of a subject or topic. It implies putting in a lot of effort, time, and attention to detail in order to gather accurate and precise information. Full definition
Years of painstaking research resulted in the Q - Fermentation method, in which specific micro-organisms naturally present in the plantation bring out the most outstanding purity and intensity from beans. (foodbeverageasia.com)
According to the sisters, Coffee Meets Bagel was created after painstaking research and analysis of other dating sites. (jobsnhire.com)
King's painstaking research into that case opened his eyes to a different case in 1957, when a white woman stated that she was raped by a black man. (bookpage.com)