The entries are compiled from questionnaires returned to the publisher by the featured subjects.
This can range from statistics, questionnaires, and articles, among many other sources.
The study, made public on Saturday, was drawn from questionnaires completed by 290,249 students who entered 552 colleges and universities last fall.
For a fee, the company arranged blind dates through the use of data collected from questionnaires.
The findings were drawn from questionnaires completed in the fall by 209,627 freshmen at 390 two- and four-year institutions.
The figures given are projections based on newly released results from questionnaires completed by 1 household in 20 during the 1990 Census.
Some applications also have the ability to collect data from on-line questionnaires and via telephone response.
Evidence was gathered in the project schools from questionnaires, interviews and observation.
The latest marketplace survey, out this week and costing $10.95, was compiled from questionnaires completed by almost 8,000 people (63 percent of them women).
"There are things that you just can't learn from questionnaires," he says.