Criteria were, criterion was

The criteria were ... the criterion was
One criterion is/was ... The two criteria were ...
More than one criterion needs to be met ... Several criteria need to be met.

One criterion, two and three criteria ...
The phenomena were ... the phenomenon was ...

These correct?

For the sake of simplicity, shouldn't we reserve a singular verb (is/was) for data in all applications? The data was being analyzed. Nobody really uses datum.

Examples below can go either way, depending upon what we're trying to convey. All examples below correct?

The jury [its members] are reaching a decision.
The jury [collective unit] is reaching a decision.

The committee [its members] are reaching a decision.
The committee [collective unit] is reaching a decision.

The family [its members] are reaching a decision.
The family [collective unit] is reaching a decision.

The organization [its members] are reaching a decision.
The organization [collective unit] is reaching a decision.

Thanks.