A research group that named Hunter College High School the saddest tweeting spot in Manhattan now says it was mistaken in its finding. The group’s acknowledgment of the error came to light after many questions were raised about an initial post on the study.

In August, the group, New England Complex Systems Institute, released a study assessing the moods of New Yorkers based on their Twitter posts. The lead researcher on the study, Prof. Yaneer Bar-Yam, told media outlets that Hunter High School, an elite public school on the Upper East Side, had the highest percentage of “negative sentiment” posts of any place in Manhattan.

This was determined, he said, by a computer program that sorted geo-tagged posts into negative or positive sentiment designations, based upon their language and emoticons.

Hunter High School was the source of an unusually high percentage of negative Twitter messages, even higher than hospital locations and spots with particularly frustrating rush-hour traffic, said Professor Bar-Yam, who offered possible reasons that included the high school’s lack of windows, high workload and the fact that the posts were collected just as the students had returned from spring break and were facing final exams.

Still, the news baffled students, faculty and alumni of the high school, and an article in The New York Times last month that focused on the reaction at the school prompted an outpouring of comments and e-mails from readers questioning the validity of the study.

Some pointed out that Hunter College High School was not mentioned in the study. Others wondered if researchers simply confused the school with the Hunters Point subway station in Queens, which itself was named as a “negative-tweeting” spot in the study.

The Times article focused on how the claim had become a talking point among students and how the news created a buzz as school reopened last month – even being cited by the administration at a welcoming assembly for students. Many students interviewed for the article pointed out that very few of their peers used Twitter and that most students were happy to be at Hunter.

Following the many comments and e-mails assailing the study, The Times contacted Professor Bar-Yam for clarification and more information. He stood by the naming of the high school and wrote, in a note. that was posted in the comments section of the online article, that he had not confused Hunter and Hunters Point.

But on Friday, after being pressed again for more information, Professor Bar-Yam said he did a more detailed analysis of the data and realized that he had incorrectly interpreted a data map that seemed to indicate that the high school was the source of a flurry of negative posts during the period of recording the data in spring 2012.

Closer analysis revealed that the posts had actually come from a single Twitter account “from a region just south of the school,” said Professor Bar-Yam, who declined to identify the account or the exact location from where the posts emanated.

The confusion occurred because the Twitter posts were recorded by location and plotted on a street map to identify locations of high and low sentiment by color code, he said, adding that the prolific tweeter near the school created “a single data area of low sentiment that overlapped with the location of the Hunter College High School.”

Professor Bar-Yam said he saw that Hunter College High School’s students were returning from vacation during the period of the data collection, and said that “this provided a rationale” why Hunter could be the source of the posts.

“While this explanation seemed reasonable to me,” he wrote, he checked the data after many “expressed incredulity that this would be the sentiment of their school.”

Although the high school was not mentioned in the published report by name, Professor Bar-Yam named it as Manhattan’s saddest-tweeting spot in response to a question from a reporter from Science magazine for an article published on the magazine’s Web site.

Professor Bar-Yam wrote an explanatory note that he requested be posted with the original article, along with “my apologies to the Hunter community.”

“I apologize for my incorrect inference about the sentiment at Hunter College High School, for which I am solely responsible, and for the subsequent reporting that cast a shadow over the positive reputation of the school,” he wrote.

He lauded “the Hunter community” for “their belief in their school.”

“Many thanks to the Hunter graduates and students who insisted that this couldn’t be the case and are helping us to improve our analysis,” he said.

Told about the error, Lisa Siegmann, the high school’s assistant principal for grades 10 through 12, called it “a perfect lesson for the students: if the data is at odds with what you know, it’s worth looking at again.”

“We teach them about the necessity of gracefully acknowledging when an academic mistake is made, and we talk (incessantly) about how easily online mis-communications can spread,” she wrote. “They’ll probably remember this example better than any of our lectures.”