A new system that allows residents to grade District government agencies has determined that city services are average but have shown improvement over the past month.

After Mayor Vincent C. Gray (D) unveiled Grade DC, the innovative testing service concludes that residents are generally satisfied with the public works, transportation, motor vehicles, parks and recreation and business licensing agencies.

All scored C’s or B’s in July after a private technology firm, newBrandAnalytics, scoured five community blogs, Facebook and Twitter, and accepted customer reviews online at Grade.DC.Gov, to evaluate agency performance.

Every agency, with the exception of the Department of Motor Vehicles’ C-minus grade, saw an improvement over their initial grade in early June.

“We think grades will continue to go up,” Gray said at a news conference to reveal the pilot program. “We are going to constantly strive to improve outcomes and won’t be satisfied until every agency gets an A.”

Gray released the grades, which he stressed are based on only seven weeks of data, a week after a Washington Post a poll found that public approval of city services has declined as the mayor continues to endure a federal investigation into his 2010 campaign.

The Post poll found that 45 percent of respondents think that the District is on the wrong track, an increase from the 36 percent who thought that way 14 months ago. Slightly more than half of all residents also said that that mayor was doing a not-so-good or poor job delivering city services.

But Gray said Tuesday that the Grade DC initiative is an example of his administration’s efforts to continue progress on efforts started by former mayors Anthony Williams and Adrian M. Fenty to improve city services and responsiveness.

“The city has improved tremendously over the last decade,” Gray said. “And we want to continue to improve how we look at the government.”

Zack Boisi, a service director for newBrandAnalytics, said the city’s $175,000 per year contract with the District enables it to compile the grades by scrolling through blog comments and other online postings while also breaking down online reviews to match target performance

The information is then run through a series of algorithms to come up with grades. The most recent grades where based on about 1,000 reviews.

Kristin Muhlner, the company’s chief executive, said she believes the District is the first state or local government in the nation to use such a grading system. Until now, she said, the grading system has primarily been used by the private sector.

City officials said grades for several District agencies jumped this month because residents appeared satisfied with the city’s response to the severe storm that knocked out power to more than 60,000 residents June 29 and downed hundreds of trees.

“We did a lot of clean-up and people realize the value we provide,” said William O. Howland, director of the D.C. Department of Public Works.

Howland noted that crews fought through 100-degree heat in the days following the storm to pick up twice as much trash as normal as residents threw out spoiled food and tree limbs.

Customers gave DPW a July grade of a B, up from a C-plus last month.

The Department of Transportation and the Department of Consumer and Regulatory Affairs both scored a C-plus in July, up from a C-minus. The Department of Parks and Recreation received a C, up from a C-minus in June.

Gray said the city plans to extend the program to 10 additional agencies this fall.