In a small room at American University, about 2,000 miles from his father's ambassadorial post in Guatemala, Frank Vincent Ortiz IV, 25, is taking his first tentative steps toward a career in Latin American political science.

There, along with another student, Ortiz has started a news service -- called "Poco a Poco," or Little-by-Little -- a news service which focuses on Central and South American political events. Five times a week, Ortiz and Marcos Poole, 23, call through news releases and wires and interview those active in Latin affairs to produce a 2 1/2-minute newscast they hook up to a telephone for interested callers.

Among the 50 to 100 callers who listen to their reports each day on 686-0690 are specialists from the State Department, embassy officials, and, of course, the CIA, Poole said.

"We frequently have information that they don't have," Ortiz said. "And that's good. I get a little tired of how things are drawn black or white in Latin America."

Ortiz traces his interest in Latin American affairs back to 1968, when his family was stationed in Lima, Peru.

"My dad woke me at four in the morning one morning to tell me that military personnel were surrounding the governmental palace and he had to take off to work," Ortiz said. "That's where it all began as far as my becoming interested in political events."

Ortiz, who lived in the United States only a year before going to college, studied international business at Georgetown University before shifting to Latin American studies at American University.

There he met Poole, whose mother is Cuban-American, and the two launched the newstape.

A small grant from the graduate program at the university pays for the $50-a-month telephone bill and lease of the tape system from the telephone company.

"I'd always been told by my father that wherever we went I represented the United States," Ortiz said. "I'm saying now, "What is it to be an American?'"

"And it suddenly dawns on you that you may not be the good guy you thought you were," said Poole, a graduate student.