Welcome to Health Reform Watch, Sarah Kliff’s regular look at how the Affordable Care Act is changing the American health-care system — and being changed by it. You can reach Sarah with questions, comments and suggestions here. Check back every Monday, Wednesday and Friday afternoon for the latest edition or sign up here to receive it straight from your inbox. Read previous columns here.

(Daniel Acker/Bloomberg)

If you want to believe Obamacare is going great, you should call up Linda Browne. She's a 62-year-old retired accountant from California who already has an appointment to see her new primary-care doctor at Kaiser Permanente, the new health insurer she signed up with through Covered California.

"I thought I would have to wait a long time," Browne says. "But when I called, they said she had an appointment Wednesday for a physical."

If you'd prefer to believe Obamacare is going terribly, then Michael D. Scott has got a story for you. He's a 36-year-old Texan who turned up at a pharmacy last week trying to fill a $700 prescription for anti-seizure medication -- only to find the technicians had no record of his enrollment.

"I'm stuck," says Scott, who takes the prescription to treat a genetic condition called Ehlers-Danlos syndrome. "I'm going to have to start buying a couple days' worth on my own if they can't figure things out. It's disappointing."

Both Browne and Scott signed up for health insurance through the Affordable Care Act. Browne has had the law work pretty well; Scott has spent hours on the phone with customer service representatives (actually, he spent one hour and 37 minutes on his last call -- yes, he timed it). And stories like theirs are about to become central to the next Obamacare fight, what I like to think of as the battle of the anecdotes.

The battle of the anecdotes is all-but-guaranteed because access to health care is really difficult to measure, even more so than the number of people who have enrolled or how well HealthCare.gov is functioning. With enrollment, for example, HealthCare.gov can track all the people who pick a private insurance plan, as can the 14-state based insurance exchanges. That's how we know 2.1 million people have selected private insurance plans (although we don't know how many have paid their first month's premium, which is due, for January coverage, by this Friday).

The federal government can gauge how well HealthCare.gov is working by tracking how long it takes pages to load, or how many enrollment files -- known as '834s' -- contain errors. And the call centers know, too, how long customers have to wait to get a person on the line.

But when it comes to access to health care, there's no analogous metric. Our health-care system is really fragmented. Since HealthCare.gov shoppers are buying private coverage, and not a government plan, we have no central clearing house to understand whether more shoppers are having an experience like Scott in Texas -- or like Browne in California.

Nonprofit institutions do study these types of questions. The Commonwealth Fund, for example, regularly looks at how long patients in different countries have to wait to see a primary-care doctor or a particular surgeon. But these surveys take months to conduct and analyze, meaning that we will probably have to wait until late 2014 or early 2015 to get a sense of what access looks like under the Affordable Care Act.

Enter the anecdote, which can be great to understand how new policy programs are impacting the way that Americans receive health care. But they can also be a really terrible way to gauge whether Obamacare is going great -- or is a complete disaster. One or two stories don't do a great job of capturing the experience of the millions of Americans who have signed up for health plans.

And even the anecdotes themselves can be nuanced, portrayed in different ways to make Obamacare seem great, or horrible. Take Browne: She called for an appointment in her new network the morning of Jan. 2. But she couldn't get through to a real, live person until that afternoon; she kept getting a message that said "all circuits are busy."

"I think of it as a really positive experience, getting my appointment so quickly," says Browne, who counts herself as a supporter of the law. "But I guess, if I wanted to be negative about it, I could talk about the circuits being busy. I just figure everything new is going to have a lot of problems."

Scott, meanwhile, is surprisingly sanguine about his situation. Yes, he is definitely frustrated with the $700 prescription he wants to fill, but can't. But he thinks of this as a transitional issue that will get sorted out. With a serious medical condition, he's happy that individual market insurers have to accept him.

"It's not dire," Scott says. "I can go to the doctor. If I have to, I can pay for one week's worth of the pills. I just worry about people who may not have that option."

Scott and Browne each have stories that tell us a bit about what Obamacare means for the American health-care system. They tell us that one person is having a pretty good experience, and one a not-so-great experience -- but even those characterizations are a bit squishy, when you dig into the nuances. No one anecdote, whether positive or negative, will give us a good sense of how the law is working for 2.1 million people. Figuring that out, unfortunately, will take a lot more than the handful of examples that will no doubt surface in coming weeks and months.

KLIFF NOTES: Top health policy reads from around the Web.

It's impossible for Obamacare to fail. "At this point, the White House's definition of success seems to basically boil down to "not failure"—a standard that falls far short for a law that used up so much political capital and was sold with such grand promises. At this point, when asked to define success for 2014, White House officials often answer by noting that the worst-case scenario for the health care law is unlikely to happen. But that "non-failure" standard falls far short of the high expectations Democrats once had for the law, and of the promises they made to sell it." Sam Baker in National Journal.

HealthCare.gov has left some Medicaid enrollees in limbo. "More than 100,000 Americans who applied for insurance through HealthCare.gov and were told they are eligible for Medicaid or the Children’s Health Insurance Program (CHIP) remain unenrolled because of lingering software defects in the federal online marketplace, according to federal and state health officials. To try to provide coverage to these people before they seek medical care, the Obama administration has launched a barrage of phone calls in recent days in 21 states, advising those who applied that the quickest route into the programs is to start over at their state’s Medicaid agency." Amy Goldstein and Juliet Eilperin in The Washington Post.