"an effective role" is a correct and usable part of a sentence in written English.
You can use it to refer to something important that someone or something is doing. For example, "The CEO played an effective role in turning around the company's fortunes."
Dr. Chalabi has played an effective role in forming civil society organizations which have effectively participated in the reduction of and the return of thousands of Iraqi families who were forcefully deported from their hones in Baghdad.
We're going to play an effective role".
But he praises the newscasts, including Tolo's, which have "played an effective role in modernizing Afghanistan" and educating the public.
This dynamic has to change if America is to have an effective role in brokering a peace.
Citizenship education equips young people with the knowledge, skills and understanding to play an effective role in public life.
European examples have shown that trade unions can, in partnership with management, play an effective role in reforming working conditions, increasing flexibility and boosting productivity.
"These are forces we can provide if an effective role and responsibility is given to Turkey," Mr. Cakmakoglu said in an interview.
It has the means and the leverage to play an effective role – but only if it can abandon the thinking of the last 15 years.
"I hope that they would be a part of the state, and have an effective role through its civil and military institutions," he said in a televised speech.
In addition, technicians and many managers lost their authority and could not play an effective role in production in the wake of the movement.
It may be that there is an effective role for targeted stop and search, in combating rising levels of knife crime, for example.
