“Nobody’s been able to get a good answer of where or when they’re meeting or how talks are going,’’ said Andres Del Castillo, a 20-year-old Suffolk University student who camped in front of the State House during budget negotiations to protest an immigration provision.

By the time lawmakers vote on the floor, it is often no more than a formality, rubber stamping what a few leaders have agreed upon in private.

During this year’s budget deliberations, lawmakers in the House and Senate did collect public testimony. And they held floor debates for several days before passing separate budget plans in each chamber. But the critical decisions at the beginning, when the budget is being crafted, and those at the end, that meld the plans, were made out of public view.

Still, Massachusetts lawmakers depend on closed doors at nearly every stage in deciding which laws to pass and which taxes to increase. Records on everything from the number of aides legislators employ to which special interests they meet with or even how some members vote in their committees are off limits. Leaders can call “joint caucuses’’ of Democrats and Republicans, allowing the entire House or Senate to meet in private.

Since the recent conviction of the former House Speaker, Salvatore F. DiMasi, on corruption charges, Senate President Therese Murray and Speaker Robert A. DeLeo have argued that transparency is a top priority and that the Legislature is more open than ever.

A lack of public access is a common complaint in state capitals from Juneau to Atlanta.

“It puts it among a handful of states who are at the absolute bottom of the barrel,’’ said Charles N. Davis, a journalism professor at the University of Missouri who researches open-government laws. “If you’re in the business of trying to self-govern, if you’re a citizen, if you’re an activist, if you’re someone who is trying to affect the outcome of legislation, it’s nearly impossible because you’re literally shut out of the process.’’

Massachusetts, the birthplace of American democracy, is one of fewer than 20 states with virtually no requirements that legislators discuss government business in public, according to a Globe review of open government data compiled by the Reporters Committee for Freedom of the Press. This state is one of about 10 in which the public does not have even limited rights to view legislators’ records.

Information blackouts are treated with an almost religious reverence by the power brokers on Beacon Hill, who frequently decline to detail what is being discussed out of what they term “a respect for the process.’’

The $30.6 billion budget approved by the Legislature last week was negotiated almost entirely in secret, with six lawmakers meeting for 24 days of talks that were off limits to taxpayers. Debates, agendas, and even the times and locations of the meetings were held in strict confidence. No minutes were kept.

Not every state legislature operates this way. Colorado is one of many states where all meetings, including party caucuses and committee meetings, are held in the open unless they involve personnel issues.

New Hampshire is one of six states to enshrine a right to open government in its constitution. There, every bill gets a public hearing, and all committee votes are taken in the open.

Vermont legislators recently revamped their open records laws to make it easier for people to sue for access to public information, forcing the government to pay attorneys’ fees if it is improperly denied.

In Florida, often considered the gold standard for open government, the law prohibits three or more lawmakers from meeting to discuss pending legislation. If they run into each other at a barbecue or drug store, they are allowed to make small talk, but they are barred from discussing an upcoming vote.

If residents there want to know which special interests are influencing a bill, they can look at lawmakers’ calendars, phone logs, or e-mails, though some legislators try to skirt that requirement by deleting often.

Conference committees, where lawmakers make the toughest decisions on what becomes law, are public in Florida. Residents can ask for charts that show which elements of a pending bill are in dispute. In Massachusetts, little about the conference process is visible.

Charlie Crist, governor of Florida from 2007 through earlier this year and a strong advocate for open government, said a history of open access has created an expectation among residents that their leaders will invite them in.

“We’re the Sunshine State where these open-government laws have been a way of life,’’ he said.

Crist, a Republican turned independent, would sometimes invite the press into the governor’s mansion to witness meals he had with the House speaker and Senate president.

When Governor Deval Patrick meets weekly with Murray and DeLeo, a practice that began decades ago to foster cooperation among the branches, the meetings are closed.

The Supreme Judicial Court ruled in 1997 that the governor is not explicitly included in the state’s open records law, allowing governors to argue that they are exempt from disclosing their full meeting schedule or the correspondence they have with lawmakers or special interests.

Leading legislators argue that adding public sessions would slow the process and that lawmakers are more candid when the public is not watching.

“The discussion [in private] becomes a lot more open and in that fashion moves the process along a whole lot faster,’’ DeLeo said.

Murray referred to the hundreds of individual amendments considered by the Senate during its marathon debate session held over two days in late May as evidence of a robust public process. Closing the conference committee between six House and Senate members is necessary, she said, because there are so many disputes to resolve.

“There are over 600, 700 amendments,’’ she said. “So if you take it out of conference and put it in the public realm, then the conferees are never going to get to finishing up the budget within the time frame we need to finish.’’

For years, open government groups have complained about a lack of public access in Massachusetts, but have been unable to create a groundswell that would force legislators to act.

Even some Republicans in the Legislature, who account for only a small minority, are reluctant to criticize the system. Bradley H. Jones Jr., the House Republican leader, said he agrees with the need to conduct some business behind closed doors to facilitate negotiations. Jones calls for a modest overhaul allowing lawmakers to decide the fate of a handful of bills in a public debate each year, without determining the outcome ahead of time.

At least a little bit of open debate, he said, would be “a good management tool,’’ for the speaker, and an opportunity for “blowing off legislative steam.’’

Noah Bierman can be reached at nbierman@globe.com. Follow him on Twitter @noahbierman.

© Copyright 2011 Globe Newspaper Company.