Evaluate the Following Generalization(s), Identifying Sample, Population, Attribute of Interest

Essay

Evaluate the following generalization(s), identifying sample, population, attribute of interest, and the extent to which the claims involved are knowable. Consider carefully the size and diversification of the sample and the extent to which the population differs or may differ from the sample; remember, what's important is that the sample be representative.
SUSANVILLE-Fewer than 20 percent of college professors consider themselves shy, according to a new study by two psychologists. "We were surprised by this result because other studies have reported that almost 50 percent of adult Americans think of themselves as shy," said Elliot Smalley, professor at Colusa State University. "College professors are sometimes thought to be an introverted lot, and so we expected perhaps a majority to think of themselves as shy," he said.
Smalley and his associate, John Mahmoud, interviewed 150 college professors who were identified by administrators at twenty-five American universities as typical faculty. The universities were selected by a random procedure from a list of American colleges and universities, Smalley said.