Instead of spending a leisurely summer in the Caribbean with her family, Shirley Robinson-Johnson, a mathematics teacher at Roosevelt High School, canceled her vacation to get some on-the-job experience in hotel management that she will pass on to her classes next month.

"Education is a business. When I approach my class this fall I will treat it as a business, a commodity," said Robinson-Johnson, who worked for six weeks this summer at the Hyatt Regency Hotel on New Jersey Avenue NW.

Johnson is one of 54 District high school teachers who took part in the public schools' "extern program," an effort activated this year to place teachers in work sites to gather information and gain experience to take back to their students.

This summer, 21 teachers worked in the health professions, banking, engineering and business. Another 33 worked with curriculum planning--revising and creating courses to make them more relevant to the work world, according to Thomas Herrmann, the school system's assistant director of corporate involvement.

Teachers who volunteer for the extern program are either paid by the company that hires them or their teaching salaries are maintained throughout the six weeks, Herrmann said.

Isaias Tekle, who has taught chemistry at Eastern High School for three years, spent six weeks at the Howard University School of Pharmacy, determining the caffeine content of aspirin and identifying organic compounds.

"By being involved in the summer program I can better see what issues to stress in class should the students become interested in pharmacy as well as health professions," Tekle said. "Chemistry is dealing with the abstract somewhat. This program will give the students the opportunity to see what they're learning in practice."

The externship program, a part of the school system's Public/Private Partnership Program, was organized by Superintendent Floretta McKenzie in September 1981. It began operating last fall after a year of negotiations with local businesses, Herrmann said. Private companies have contributed more than $2.5 million in funds and personnel to the program in its two years.

"Through corporations hosting teachers, they became more aware of the reality of the work place and now can relate it to the school," said Herrmann.

Physics and mathematics instructor Willard W. King, also of Eastern High School, said that although his externship this summer was "strictly observational, I can now bring to those taking physics a unit of work that is better organized." He said it will help students "understand that what they are doing in class is actually being used in hospitals and the medical profession."

King shadowed the daily duties of staff professionals in D.C. General Hospital's biomedical and engineering department. He said he observed the hospital staff testing equipment, such as kidney dialysis and X-ray machinery, for broken electrical circuits and excess gas buildup.

King, who has taught at Eastern for five years, has arranged an exchange program to bring medical professionals from D.C. General into his classes to lecture on medical careers. Students from Eastern who express interest in health professions would go to D.C. General for experience in the field, one of the goals of the summer externship program, King said.