moondaugther,

What you say is correct. But that wasn't the point I was trying to make.

Suppose a doctor gives me a drug promising that it would halve my tremor, while not making anything else worse. I take the drug and it does just that. It has done exactly what I was told it would do: it has met 100% of my expectations. But, even if we only consider tremor, it has only met half my need.

Perhaps this is one of the occasions where UK English and US English differ. For instance, in the UK we tell our children to walk on the "pavement"!

John