On Monday, the justices agreed to provide the definition, accepting a case that began in a Memphis rail yard when the only woman working in the maintenance department there complained about sexual harassment by her supervisor.
Within 10 days, the woman, Sheila White, was transferred from her assignment operating a forklift to the less desirable position, within the same job classification, of working outdoors on the tracks.
Three months later, after she filed a formal complaint with the federal Equal Employment Opportunity Commission, her employer, the Burlington Northern & Santa Fe Railway Company, suspended her without pay. After a union grievance, she was restored to the payroll with back pay after 37 days.
The question for the court is whether the United States Court of Appeals for the Sixth Circuit, in Cincinnati, correctly concluded that those events amounted to the type of retaliation that Title VII of the Civil Rights Act of 1964 prohibits. The appeals court upheld a jury award of $43,250 in compensatory damages to Ms. White.
In its appeal to the Supreme Court, Burlington Northern & Santa Fe Railway Co. v. White, No. 05-259, the railroad is arguing that any injury to Ms. White was so minimal and transitory as to fall below the threshold of the type of adverse action that should count as discrimination.
Only "ultimate employment decisions," like dismissal or demotion, should count, the railroad argues, while "minor and interim employment actions should not be actionable retaliation."
The issue, which has arisen in every federal appellate circuit, is one of increasing importance in labor law, because retaliation complaints account for the fastest-growing type of discrimination case. More than a quarter of all discrimination cases filed with the E.E.O.C., some 20,000 cases in 2004, allege retaliation.
The issue is particularly important in sexual harassment cases, because in defining the legal protection against sexual harassment on the job, the Supreme Court has ruled that employers are not liable unless the employee has first brought the problem to a supervisor's attention. The requirement of making a complaint can thus make these employees particularly vulnerable to retaliation.
Among the 12 federal circuits to have ruled on the question, two have accepted the "ultimate employment decision" test, the most employer-friendly of the variations the courts have devised. Another agrees with the E.E.O.C. that an action likely to produce a chilling effect, deterring employees from making complaints in the future, should count as prohibited retaliation.
The Sixth Circuit and the eight others applied a test requiring a "materially adverse change in the terms of employment."
The railroad argues that even if that is the proper definition, the circumstances of this case did not satisfy the test. Ms. White's lawyers vigorously disagree, citing in their brief the finding by the judge who heard the case in Federal District Court in Memphis that back pay alone could not compensate Ms. White for the "total insecurity" and depression she suffered during her suspension.
These were among other developments at the court:
School Transfers
Without comment, the court turned down a challenge to a school choice plan in Lynn, Mass.
The ethnically diverse city of 80,000, north of Boston, adopted the plan four years ago to enable students to transfer from their neighborhood schools without, at the same time, disturbing the racial balance of individual schools. Transfer requests are generally denied if they would have the effect of making the sending or receiving school less balanced.
A group of parents filed suit, contending that the plan was based on an impermissible use of race. They lost in Federal District Court and in the United States Court of Appeals for the First Circuit, both in Boston. The appeals court held that the plan promoted the "compelling state interest" of achieving and maintaining racial diversity.
In their Supreme Court appeal, Comfort v. Lynn School Committee, No. 05-348, the parents argued that the appeals court had mistakenly endorsed a "permissive use of race" that they said "dooms generations of children to the damaging experience of being turned away at the school house door for having the wrong skin color."
As it made its way through the lower courts, the case attracted considerable attention as a potential follow-up to the Supreme Court's 2003 decision upholding affirmative action in admission to the University of Michigan's law school.
Chief Judge Michael Boudin of the First Circuit, in an opinion concurring in the decision that upheld the plan, said the appeals court had to exercise its own judgment because there was no Supreme Court precedent that directly governed the case. The Lynn plan "is fundamentally different from almost anything that the Supreme Court has previously addressed," Judge Boudin wrote.
Insanity Defense
Accepting an appeal from a man who was convicted of murdering a police officer at the age of 17, when he was suffering from paranoid schizophrenia, the court agreed to review Arizona's approach to the insanity defense.
The Arizona Legislature has adopted, and the state's Supreme Court has upheld, a definition of criminal insanity much narrower than that used by most other states.
Under Arizona law, a defendant must prove, by "clear and convincing evidence," that he was suffering from "a mental disease or defect of such severity that the person did not know the criminal act was wrong."
Arizona does not allow the introduction of mental health evidence to argue that the defendant could not have formed the necessary intent to commit the crime.
In this case, Clark v. Arizona, No. 05-5966, there was no dispute about the diagnosis of schizophrenia in Eric Michael Clark; the state's expert witness testified that the boy had been delusional when he shot the officer.
But the trial judge, who heard the case without a jury, found the defendant guilty of murder on the ground that he knew that what he was doing was wrong.
The sentence was 25 years in prison without parole. The Arizona Court of Appeals upheld the verdict on the basis of state-court precedents interpreting the Arizona insanity defense.
In appealing to the Supreme Court, Mr. Clark's lawyer asserts that Arizona "appears to stand alone" in having adopted too narrow an approach as to have effectively abolished the insanity defense
The Supreme Court has never directly ruled on whether states must provide such a defense. In this case, the lawyer, David Goldberg, argues that the law deprived Mr. Clark of due process and of the right to put on a full defense.