The phrase "painstaking study" means putting in a lot of effort, time, and attention to detail when examining or learning something carefully. Full definition
We can not answer this question without understanding the Preaching, nor understand it without painstaking study of material which in some of its forms is strange and elusive; but without answering this question, we can not confidently claim the name of Christian for that which we preach. (religion-online.org)
To transcend the technical challenges, Roth and UNC colleagues, including postdoctoral fellows Sheng Wang, PhD, and Daniel Wacker, PhD, conducted a series of painstaking studies over several years — outlined in the Nature paper — to coax DRD2 to crystalize while bound tightly to risperidone. (sciencedaily.com)
There are of course many fragments for which one would wish to propose an identification only after the most painstaking study, and even then perhaps only tentatively; these would include OH11, 14 and 15, which the AiG article so glibly claims as «the true human kind». (talkorigins.org)