Iraq says new scientific techniques should prove how much was destroyed.
The techniques proved successful in improving memory immediately after the subjects learned them.
This technique has not proven to be very successful though.
No one seemed to know whether these new techniques would prove more durable than their predecessors.
This technique has proved to be very effective in practice.
"Having said that, those techniques have proven to be consistently and completely wrong."
The techniques had proved effective in a large body of work on other diseases.
His technique proved lasting and has had a major impact in modern medicine.
This technique proved inadequate when better research on the effects of nuclear weapons became available.
But the techniques needed to create it might prove very useful in other chemical processes.