The American health care system is a complicated beast. Obamacare has hopes of simplifying it through its online health care marketplaces, which are designed to spur competition between vendors, but according to a new survey, most Americans are still in the dark when it comes to buying health insurance.

Words like “deductible” and “premium” may be written into the Affordable Care Act hundreds if not thousands of times, but according to the newly published survey, most uninsured Americans can’t even begin to define them. Along with general knowledge about Obamacare, the new exchanges, and the March 31 enrollment deadline, many respondents lacked the knowledge that the online marketplaces even existed — a fact that gives the study authors great concern given the impending deadline.

“The ultimate success of the Affordable Care Act (ACA) depends on how well the health insurance exchanges can bring the benefits of private competition to individuals in the form of lower premiums,” the team wrote. If the people who need the lower premiums the most can’t access them, because they just don’t know about them, or they aren’t informed enough to make the smartest choice, then the exchanges aren’t accomplishing their goal.

Overall, only 17 percent of uninsured Americans had a fair/great deal of knowledge about the ACA; 36 percent knew about the exchanges, and 31 percent knew about subsidies offered to them through the exchanges. Forty-two percent could explain that a deductible is the amount of money a person has to pay before health insurance kicks in.

One hopeful sign is that the study was conducted in August and September of 2013, long before the website was fully functional, let alone boasting over five million users. On March 18, the administration showed was totaling 50,000 new enrollments per day.

“With only two weeks to go, we’re continuing to work hard to ensure that every American who wants to enroll in affordable coverage by the deadline of March 31st is able to do so,” the administration said in a blog post.

Still, the only knowledge likely to have increased between September and the enrollment deadline is the knowledge about the online marketplace. Consumers may be able to find insurance plans they can afford, but whether they are the best plans is a separate concern. Particularly at risk, the researchers noted, are low-income families. “This group is ineligible for Medicaid and could benefit from the exchanges. They appear at high risk of making poor decisions when shopping for health insurance.”

The researchers push for more simplified versions of the website in which default options must be overridden, rather than selected actively, for consumers to make more advanced choices. They refer to a silver, gold, and platinum coverage range to maximize insurer competition for the least costly plans.

What’s more, if an uneducated consumer has too much choice at his or her disposal, “such defaults that limit choice unless the consumer chooses to override the default, are probably welfare-increasing.”

Source: Barcellos S, Wuppermann A, Carman K, et al. Preparedness of Americans for the Affordable Care Act. PNAS. 2014.