SAN JOSE, Calif. – A federal judge said yesterday that he will require Google to give the government some of the data it has demanded for use in a long-running lawsuit relating to pornography on the Internet, but he did not seem inclined to force the company to turn over potentially-sensitive information, such as search queries submitted by individual Web users.

“It’s my intent to give some relief to the government,” Judge James Ware said after hearing nearly 90 minutes of argument in a packed courtroom in the heart of Silicon Valley. “What I need to study is how to shape it,” the judge said.

During the hearing, lawyers for the Justice Department and for the search giant acknowledged that the government has substantially cut back its initial request, which asked Google to turn over billions of Web addresses in the firm’s index, as well as millions of search queries. The government is now seeking just 50,000 addresses, also called uniform resource locators, and only 5,000 searches. But Google is continuing to resist.

Judge Ware expressed repeated concerns that the subpoena could improperly burden Google and invade the privacy of some of the company’s customers. He noted that Google is not a party to the underlying case, a lawsuit the American Civil Liberties Union brought in Pennsylvania to block the federal government from enforcing a 1998 law, the Child Online Protection Act, which is aimed at preventing minors from seeing sexually explicit material on the Internet.

A Justice Department attorney, Joel McElvain, said the government needs the data to help answer a key question in the lawsuit: whether Internet filtering software is effective. “The government is not seeking any personally identifiable information,” Mr. McElvain said.

However, an attorney for Google, Albert Gidari Jr., said all kinds of personal information, including Social Security and credit card numbers, could be part of a search query. “It might make a statement about the sexual preferences of a public figure,” he said. “If you were one of those people, I don’t think you would want that in third-party hands.”

Mr. McElvain noted that Google regularly publishes its most popular searches as part of its “Zeitgeist” feature and Google’s advertisers and others routinely get some queries from Web browsers. The government lawyer also promised that any data produced would not be used for any purpose beyond the law suit.

Judge Ware seemed dubious about that assertion. He asked what would happen if one of the search queries included the name of one of his law clerks, along with that of Osama bin Laden. “Are you telling me the government would ignore it?” the judge asked.

“Yes, I am,” Mr. McElvain replied. He said the fact that someone searched for the two names would have no significance. “There’s no real information to be gleaned from that,” he said.

Judge Ware also questioned the government’s assurances that the data would be protected from disclosure. “I don’t know how you do that in a case where you’re trying to prove something at a public trial,” the judge said.

In civil lawsuits, subpoenas are routinely enforced as long as the information sought might lead to admissible evidence. Judge Ware said the stakes are somewhat different when the government is seeking the information. “Ordinarily, the government, in order to get information, would have to be very careful because the Fourth Amendment protects us from searches and seizures,” he said.

The judge said he was “very reticent” to conclude that the information sought was irrelevant to a case pending across the country. However, he also noted that the government was not seeking direct evidence, but trying to force Google to cooperate in a research study. “Lots of people want to do studies,” the judge said.

Mr. McElvain noted that Yahoo, America Online, and Microsoft have already complied with similar requests. He conceded that the Google data were not essential, but he said the company’s information would “improve” the quality of the study.

Judge Ware observed that Google’s dominance in the search field all but guaranteed that the government would seek the company’s data. “You’re the best. You’re the biggest. You made yourself so,” he told the firm’s lawyers.

During the hearing, the courtroom sometimes sounded more like a computer convention, as the judge and the lawyers batted about terms such as “source code,” “random number generator,” and even “crawl depth.”

The judge also inquired several times about the financial cost to Google, a discussion that seemed somewhat comical in light of the company’s $104 billion market value. The government said it would reimburse the firm for whatever expenses it incurs to produce the data.

As the session concluded, Judge Ware seemed to favor giving the government the sample of indexed Web addresses, but to reject or further limit the request for search queries. He said he would issue a formal ruling “very quickly.”

A Google attorney, Nicole Wong, said later that the firm was “very pleased” with the hearing. “At the very least, we have come a long way from the initial subpoena from the government,” she said. “I think the biggest concern is what the precedent is.”

Last August, the government directed subpoenas to Google, Yahoo, Microsoft, and America Online, seeking the address of every Web page cataloged by those services as well as the text of all searches conducted during a two-month period last summer. All the firms except for Google have said publicly that they have complied with the subpoenas. Spokesmen for the companies said they negotiated more limited responses than the government initially sought.

More than 30 companies offering Internet filtering services also received demands to turn over information for use in the ongoing litigation. Those subpoenas sought data on how often the filters are used and how much of the Web they deem pornographic.

The Justice Department released copies of the subpoenas to The New York Sun in response to a Freedom of Information Act request.