The Supreme Court agreed yesterday to try to define how far police may go in using a standardized "profile" of criminal traits as a reason to approach and question a person.

The justices will hear an appeal by Florida prosecutors challenging a decision that threw out the conviction of a man found carrying 65 pounds of marijuana at Miami International Airport.

The case began in 1978, when two plainclothes detectives of the Dade County Crime Bureau stopped Mark Royer at the airport because he conformed to the department's psychological and physical "profile" of possible drug couriers.

A Florida appeals court reversed Royer's conviction and declared the search illegal, concluding, "All narcotics couriers act like parts of the profile, but most people who act like parts of the profile are not narcotics couriers."

In other action yesterday:

The court dealt a blow to the embattled air traffic controllers union, refusing to hear its argument that federal courts may not block strikes or other job actions by federal workers. The case stemmed from a "slowdown" the union undertook a year before its nationwide walkout last August.

The court agreed to decide whether prosecutors may increase the charges after a criminal defendant decides to have a jury trial.

The court said it will review a ruling that appears to bar most such acts by prosecutors in Maryland, Virginia, North Carolina, South Carolina and West Virginia.

Learley Reed Goodwin was stopped for speeding on the Baltimore-Washington Parkway on Feb. 2, 1976. Goodwin sped away when officers attempted to question him, and the car swerved, knocking down an officer.

When apprehended, Goodwin was charged with various misdemeanors, including one count of "assault by striking" an officer.

After Goodwin requested a jury trial--rather than pleading guilty or submitting to a trial before a federal magistrate--prosecutors increased the charges to felonies, more serious crimes carrying stiffer sentences.