The phrase "a powerful assumption" is correct and usable in written English.
It can be used when discussing a belief or idea that is strongly held and influences thoughts or actions.
Example: "The study was based on a powerful assumption that all participants would respond similarly to the treatment."
Alternatives: "a strong belief" or "a significant presumption."
"Guleghina's powerful assumption of the tormented Druid priestess was a lesson in dramatic conviction and vocal and musical mastery," said the critic of El Mundo.
The most powerful assumption about cancer education, though, was that its central message should be that "early cancer is curable".
"Actual Innocence," by two prominent New York criminal defense lawyers and a columnist for The Daily News, raises a powerful challenge to the assumption that all is pretty much well with the legal system, and that the safeguards against wrongful conviction are adequately in place.
What women alone appear to encounter is a powerful set of negative assumptions associated with motherhood.
In a powerful section questioning economic assumptions that govern modern societies, the archbishop takes issue with the idea that growth, defined as increasing production, is necessarily a good thing.
When used in actuarial calculations, that assumption has a powerful effect.
To show them that writing is both bomb and bomb disposal – a necessary shattering of cliche and assumption, and a powerful defusing of the soul-destroying messages of modern life (that nothing matters, nothing changes, money is everything, etc).
It then seems that when an assessment reform is imposed by a powerful body with the wrong assumption of homogenous schools in terms of staff and resources, it is only natural for such problems to arise and for the reform to fail to take root.
The collection of UFR information in the post-2008 NHANES cycles provides a powerful tool for assessing this assumption.
