SAN FRANCISCO (AP) — Getting rid of racist, sexist and other hateful remarks on Facebook is more challenging than weeding out other types of unacceptable posts because computer programs still stumble over the nuances of human language, the company revealed Tuesday.

Facebook's self-assessment showed its policing system is far better at scrubbing graphic violence, gratuitous nudity and terrorist propaganda. Automated tools detected 86 percent to 99.5 percent of the violations Facebook identified in those categories.

For hate speech, Facebook's human reviewers and computer algorithms identified j...