But few programs have been studied enough to be proved effective.

No one yet knows whose voices will prove most effective.

When it came my turn, however, he was to prove less effective.

The change went into effect in January 2007, and has proven effective.

Our army is small but it has, over the years, proved effective.

This study has also been proven very effective by various studies.

This may prove more effective if the girl playing the wife has no idea of what the scene is going to be about.

We will have to wait and see whether or not these measures prove effective in practice.

Two strategies have proved particularly effective for the market leaders.

"Many things have yet to be proven safe and effective."