Three months into his tenure on the Supreme Court, Chief Justice John Roberts has yet to emerge fully from the shadow left by his predecessor or hint at any change in the court's direction.

The Supreme Court visitor's guide still features a photo of the late Chief Justice William Rehnquist. And every half-hour, the visitors' theater shows a video that includes a narrative by Rehnquist on how the court works.

Inside the courtroom, Roberts' fresh friendliness sharply contrasts with Rehnquist's brusque style. The new chief justice has an almost boyish enthusiasm in the welcomes he extends to lawyers inducted to the Supreme Court bar at the start of each morning session. The speech is the same, but Roberts delivers it with a smile.

At 50, the court's youngest member is flanked on the bench by 85-year-old Justice John Paul Stevens and 75-year-old Justice Sandra Day O'Connor.

"For Roberts, it's brand new," said Duke University law professor Erwin Chemerinsky, who has argued before the Roberts court, fielding a dozen questions from the new chief.

Roberts seems to perch on the edge of his seat. He cracks jokes and smiles at other justices' attempts at humor.

"In some ways, Chief Justice Roberts is more open," said Viet Dinh, a Georgetown Law School professor and former Supreme Court clerk. "He has a more welcoming countenance. He's younger. He smiles more."

Rehnquist, who was on the court 33 years before his death last fall, "was more of an interested spectator and overall umpire rather than a participant most times," Dinh said.

Before joining the bench as an appeals court judge in 2003, Roberts was a veteran Supreme Court lawyer and had argued 39 times before the justices. He first came to the Supreme Court after graduating from Harvard Law School to clerk for Rehnquist.

Rehnquist was known for getting his opinions done speedily, even while battling cancer. As chief justice, Roberts' pace so far has been average. And overall, the court is running slightly behind the number of signed opinions released by this time a year ago -- 13 then compared to 11.

At the same time, the court has yet to rule on some of the more controversial cases argued since Roberts took over as chief justice, including doctor-assisted suicide, abortion, religious freedom, capital punishment appeals and a protest over gay rights.

Further complicating resolution of some cases is the impending departure of O'Connor, a moderate who often casts the deciding vote on issues ranging from abortion to religion. If the justices are split 4-4 on a case without her vote, court members who differ with her position could force a delay in the release of the opinion until her successor is on the bench.

The Senate Judiciary Committee held hearings last week on whether to confirm conservative Judge Samuel Alito to succeed her.

So far, Roberts has penned one ruling, a straightforward unanimous decision in a case involving lawyer fees. He has had to take himself out of the consideration of some cases because of conflicts, but so far the recusals have not caused problems resolving cases.

As chief justice, Roberts runs the private weekly meetings of the justices and assigns the writing of opinions when he is in the majority. He has been in the majority in every case but one, an appeal that he took himself out of, apparently because of a conflict with his previous law firm.

Of the opinions released so far, Justice Antonin Scalia appears to have the highest-profile assignments -- writing the court's opinion in a 5-4 death penalty case and a unanimous victory for the Bush administration defending a disabilities law.

Roberts, like Scalia, can be an aggressive questioner.

Recently, for example, he interrupted a lawyer for the state of Michigan with sharp words, "That's not true." A few minutes later, he seemed equally unsatisfied with the arguments on behalf of a Michigan man contesting the search of his home.

Roberts can also be humble in posing queries. He started one question recently with, "Maybe this is something everybody knows but me."

Justices were used to being chided by Rehnquist when they asked too many lengthy or off-the-point questions. Roberts does not cut off questioning. He often interrupts lawyers during their closing rebuttal statements with more questions, something Rehnquist did not like.

In at least one ruling, the case involving the disabilities law, Roberts appeared to find common ground. That ruling had been expected to be fractured, but during the oral argument Roberts suggested that the court resolve it on very narrow grounds. That is what happened.

A.E. Dick Howard, a Supreme Court expert at the University of Virginia, said that Roberts might be able to persuade his colleagues to reach consensus more often, and the result could be fewer split opinions.

"He might be more of a lawyer's judge than Rehnquist was," Howard said.