The public’s impression of HealthCare.gov, the Obama administration’s online health insurance marketplace, remains deeply negative two weeks after its troubled launch, according to an analysis of Twitter sentiment .

That's a reversal from what was happening in the weeks leading up to the Oct. 1 launch of the online insurance exchange, when more tweeters expressed positive opinions about HealthCare.gov than negative opinions, according to an analysis by Topsy , an analytics firm that mines Twitter to gauge public sentiment.

The marketplace’s sentiment score shot up a few days before the public launch, spurred mainly by tweets from news organizations urging people to check the site out, according to Topsy’s analysis. That sentiment score dropped precipitously once the online marketplace was online and has remained low ever since. (See the graph below).

Topsy’s “sentiment score” for HealthCare.gov has hovered between 10 and 15 on a scale of 1 to 100 since Oct. 3. The company uses a keyword analysis of tweets mentioning HealthCare.gov to determine whether tweets are positive or negative. A score of 50 out of 100 essentially means there are an equal number of positive and negative tweets, a spokeswoman said.

The sentiment score for the president’s overall healthcare reform, popularly known as Obamacare, suffered a similar decline in sentiment after Oct. 1 but has only dropped to a score of about 30 out of 100.

The analyses don’t measure sentiment since the end of the partial government shutdown on Thursday, after which more of the public’s attention may have been freed up to focus on Healthcare.gov.

After the shutdown ended, the Republican National Committee shifted its focus to the online marketplace’s troubled launch, including a Twitter campaign urging the president to fire Kathleen Sebelius, secretary of the Health and Human Services Department, which is largely responsible for implementing the new law.

Software failures have plagued HealthCare.gov since its launch, drastically reducing the number of people who were able to enroll in insurance programs through the federal site and frustrating some state exchanges that rely on federal data. The federal site also suffered from insufficient server capacity during its first days, according to U.S. Chief Technology Officer Todd Park.

Less than 1 percent of visitors to HealthCare.gov have successfully enrolled in insurance programs using the site so far, according to figures from the market research firm Millward Brown Digital.

The largest share of people left HealthCare.gov because their attempts to register with the site -- one of the first phases in the enrollment process -- failed, Millward Brown found. IT experts have warned there may be more software troubles that haven’t yet been uncovered because people have been halted at the registration phase.

An early version of HealthCare.gov came online several months ago, but the components of the site that allow uninsured people to research and enroll in insurance plans launched at the beginning of this month. HealthCare.gov runs insurance marketplaces for 36 states and provides data for 14 states and the District of Columbia, which are running their own exchanges.

( Image via Maksim Kabakou / Shutterstock.com )