Facebook COO Sheryl Sandberg on Wednesday called the site's psychological research conducted on nearly 700,000 unaware users "poorly communicated," the Wall Street Journal reported.
Sandberg delivered the first public comments from a company executive since social media users reacted negatively to the study over the weekend, the Journal wrote.
"This was part of ongoing research companies do to test different products, and that was what it was; it was poorly communicated," said Sandberg. "And for that communication we apologize. We never meant to upset you."
The one-week experiment, which took place in 2012, attempted to determine if lowering positive or negative feedback in users' news feeds would prompt them to post more positively or negatively.The results were published in the March issue of the Proceedings of National Academy of Sciences.
Sandberg made the comments while in India meeting with businesses that advertise on Facebook. Read the Wall Street Journal's full story here.
— By CNBC staff