Three polls released on Tuesday show President Obama doing better / doing worse / doing much worse than he was in previous surveys, which should lead to some relief / alarm / panic in the White House.

The new surveys are from Pew Research, McClatchy-Marist, and Quinnipiac University, respectively. Each offers a summary of its findings.

Pew:

For the first time since last spring, Barack Obama’s steadily declining job rating has shown a modest improvement. And while his signature legislative accomplishment — the 2010 health care law — remains unpopular, Obama engenders much more public confidence on health care policy than do Republican leaders in Congress.

McClatchy:

The American public is unusually pessimistic about the direction of the country and increasingly fed up with Washington gridlock, a sour mood reflected in the worst disapproval ratings for President Barack Obama since he took office nearly five years ago.

Quinnipiac:

President Barack Obama's job approval among American voters drops to a new low, a negative 38 - 57 percent, as the outlook for Democrats running for Congress and the U.S. Senate fades also, according to a national poll released today.

Those are remarkably different assessments. What gives?

The actual numbers, at right, show that in each poll Obama is underwater. Pew has him at a -4 percent net approval (percent who approve of his job performance minus the percent that disapproves). McClatchy has -10; Quinnipiac, -19. That's a pretty wide spread, even though the actual approval ratings — 45, 43, and 38, respectively — aren't that different.

But it isn't just that Pew finds the highest approval that prompts its more rosy assessment. The bigger factor is likely the net change in each poll. At right are the net approval values for each pollster between today's results and the one previous. McClatchy and Quinnipiac both see Obama's numbers dropping. Pew sees his numbers improving.

Why the wide swing? Because different polls are taken at different times and use different questions (and, sometimes, methodologies). When Anthony Weiner apparently plunged 12 points in the polls over the summer, we spoke with Columbia University professor Andrew Gelman, who suggested that, given a number of polls, "the natural thing to do would be to average them." Each is measuring a slightly different region of the range, after all.

So, averaging them, we see that Obama's got an approval / disapproval split of 42 / 53. The right reaction is probably the middle one: alarm. Especially since, on average, his net approval dropped a point (form an average of -10 to an average of -11) since the last set of polls.