Common Mistakes : Collaboration

noun

.BAD: The police were grateful to the public for their collaboration
.GOOD: The police were grateful to the public for their co-operation

Collaboration comes from the verb collaborate = work in partnership with someone on the same task, especially one of a scientific, artistic or industrial nature
He was one of the scientists who had collaborated with Oppenheimer to produce the first atomic bomb

Co-operation comes from the verb co-operate = be willing to help someone to achieve something; be helpful
Faced with the threat of a full-scale military invasion, the general had no choice but to co-operate