The Pew survey was based on telephone interviews in April with two nationwide samples of adults 18 and older.

Then in the mid-70's, I did a nationwide sample of therapists to find out what their cases were like.

The findings were based on a nationwide sample of 2,045 adults reached by telephone from July to September 1990.

The figures were based on a nationwide random sample of students who were asked whether they had been victims of crime.

And the last would be a random nationwide sample to check for accuracy.

The increasing incidence of newborn circumcision: data from the nationwide inpatient sample.

In addition, the original plan called for the census takers to conduct interviews with a nationwide sample of 750,000 households.

That's why a poll of Iowa or South Carolina is worth far more right now than a nationwide sample.

It is the first time such numbers have been collected in a nationwide scientific sample.

But the schools had all volunteered to participate in the survey, making them somewhat less representative than a broader nationwide sample would have been.