In recent weeks, a flood of highly-touted evaluations, studies, and analyses of the state of Iraq have generated numerous headlines. But which ones are the most trustworthy, and which ones are going to matter the most (two categories that are often, sadly, independent)?

Here's a handy summary of how to tell them apart, and what you need to know about their conclusions. (Updated September 10, 2007.)

REPORT:
Testimony of General David Petraeus and Ambassador Ryan Crocker to the House Foreign Affairs and Armed Services Committees on September 10.

ABOUT THE AUTHORS:
General Petraeus has been the top military commander in Iraq since February 2007. Ambassador Ryan Crocker has served in the Middle East since the 1970s; he survived the U.S. embassy bombing in Beirut in 1983. In regards to Iraq, he told NPR on June 6 that "I don't see an end game, as it were, in sight."

METHODOLOGY:
Based on Petraeus's and Crocker's on-the-ground experience in Iraq. Petraeus began his testimony by stating that the following assessment was his own, and had not been cleared by the White House (contrary to an LA Times story that "it would actually be written by the White House.")

CONCLUSIONS:
"The military objectives of the surge are in large measure being met," Petraeus said. Troop cuts could begin this month with the removal of a Marine unit and continue through July 2008 with the removal of 30,000 troops, returning to the pre-surge troop levels of 130,000. He would not speculate on troop reductions beyond next summer. Crocker said that "We must acknowledge that 2006 was a bad year in Iraq," but thought the surge had made a difference. "A secure, stable democratic Iraq at peace with its neighbors is attainable," he said, lamenting that there wasn't a Nelson Mandela-like figure to help lead Iraq. He joined Petraeus in warning of the potential that Iran would gain influence in Iraq if the U.S. failed.

WHY IT'S PARTISAN:
The testimony essentially amounted to Petraeus grading the progress of his own work in Iraq. He parroted the White House line pretty exactly. And the head of the nonpartisan Government Accountability Office, David Walker, questioned the legitimacy of the statistics used by the military to track sectarian violence.

WHY IT'S OBJECTIVE
Petraeus is arguably in the best position to evaluate the big picture of our military strategy there and provide recommendations on how to move forward.

THE TAKEAWAY:
It certainly received a lot of hoopla, but Petraeus's and Crocker's testimony leaves the situation in Iraq exactly where it was. The announcement of some troops coming home next year is receiving attention, but it's not really news: As Army Chief of Staff General George Casey said last month, "The surge was and remains a temporary function.''

INFLUENCE ON A SCALE OF 1 TO 10 (with 1 representing an anonymous blog-commenter and 10 representing General Petraeus):
10, by definition, though maintaining the status quo is likely to be its legacy.