This is likely because there are few studies examining follicle number in normo-ovulatory women and it is nearly impossible to study follicle number and menopause in the same cohort of women in all previous studies on menopause, data on follicle number were not available or would have likely been too low to measure.
On the one hand its importance in the cognitive economy (or even its very existence) was now subject to doubt; on the other hand it had come to seem that it was very difficult, if not impossible, to study it experimentally and objectively.
Fewer than one in 10,000 people take such a step, so it's been almost impossible to study the social and psychological precursors of this action.
However, most studies have a cross-sectional study design, therefore it is impossible to study causality between inflammation and affect, in contrast to idiographic studies.
"When I am doing an excavation, for me it's impossible to study only one thing and not look around me". Serrallonga's first expedition to Africa was not the only important event that year in his career.
Though he had dropped out of high school -- it had been impossible to study at home, he said, and he was too depressed to concentrate -- he read voraciously.
Whereas classical behaviorism had viewed the mind as impossible to study scientifically because its states and operations are not directly observable, Miller began to argue that mental phenomena were a legitimate subject of psychological research and that they could be studied through empirical and objective means.
Perinatal death is impossible to study in small scale settings and large datasets are needed, such as that provided by the MBRN.
For half a century, social scientists and philosophers had told themselves that the mind was murky and amorphous, impossible to study in a rigorous way, so it was better to ignore it.
