The phrase "a large and effective" is correct and usable in written English.
It can be used to describe something that is both significant in size or quantity and successful in achieving its intended purpose.
Example: "The organization implemented a large and effective marketing campaign that significantly increased their customer base."
Alternatives: "a substantial and efficient" or "a considerable and impactful".
He quickly built a large and effective navy from a few ships and a force reduced by the departure of Confederate sympathizers.
The fifth of these annual festivals -- a large and effective project in the name of nationwide jazz education -- will start with 15 high school bands and end with one winner.
These nanoparticles are known to have a large and effective application in clinical microbiology.
We seem to want a purity of spirit and behavior in our elected officials that seems completely unrealistic to me -- but that said, what I can say is that O'Malley is of the policy caliber and demonstrates a rare management excellence over a large and effective state bureaucracy that makes him a very credible candidate for the US presidency.
Thus, the high genetic variation during the LGM most likely reflects a large and stable effective population size during the dry and cold climatic conditions of the Polar Ural and adjacent regions during this time [49], which are optimal for collared lemmings.
Our results suggest that annual CDTI has a large and highly cost-effective impact on human health.
A8 Push to Upgrade U.N. Forces Ambassador Richard C. Holbrooke said the United Nations must transform its civilian-run peacekeeping department into a larger and more effective military-style operation.
Ambassador Richard C. Holbrooke said today that the United Nations must transform its civilian-run peacekeeping department into a larger and more effective military-style operation if it is to avoid repeated humiliations in the riskier missions it is undertaking around the world.
Najibullah managed to hold out for three years before his government collapsed, despite a larger and more effective civil service, military and political team than exists under President Hamid Karzai today.
So it has turned to an unlikely saviour: Unison Capital, a Japanese investment fund, to which it has offered a large stake and effective control.
It is a unique sort of campaign," the Times commented, "as it probably marks the first attempt at a large scale and effective organization of this class in the history of American politics".
