The phrase "largely effective" is correct and can be used in written English.
Example: The new policies implemented by the company were largely effective in reducing costs and improving efficiency.
Despite this, Sweden has built one of the most egalitarian societies in the world because of its large, and largely effective, welfare state.
"The ad has been largely effective because it wasn't rebutted".
There's no question that Germany's efforts to overcome its past were sincere and largely effective.
THE BOTTOM LINE According to research, the "mother's kiss" remedy appears safe and largely effective.
Sullivan believes the German capital's efforts to avoid falling into "the London trap" are laudable – and largely effective.
And the agency is working with a contraceptive that is largely effective for two years in mares.
But we do know because there has been plenty of research showing that such education is largely very effective.
Abortion rights leaders dismiss the objections, and say this method has proved largely safe, effective and — to the surprise of some — perfectly acceptable with most patients.
The Wolverines, who entered the night with the country's third best adjusted defensive efficiency, have largely been effective in disrupting the flow of Villanova's starting five on the offensive end.
Although today's disruption is largely digital, effective strategy is always informed by hard-earned industry knowledge and C-suite insight.
What constitutes "information" on a DNA microarray is largely the effective binding of a probe to its target sequence, in the absence of cross-hybridization of non-target sequence; this is a universally desirable property, regardless of the microarray application.
