In the unconscious bias training video that Google released a year ago, its director of people analytics Brian Welle said, “We’re probably the vanguard of what’s going to happen in this space.” He can drop theProbablynow.

Their unconscious bias trainings cost $3,000 to $5,000 a pop for 30 to 50 people, though companies can get a volume discount.

VayaCould have made thousands of dollars a month if we had agreed to just do trainings, 75% of which would have been unconscious bias trainings, but we were fundamentally not interested in helping companies check a box,” said Nicole Sanchez, who founded Vaya and joined GitHub in May. A rash of startups, buoyed by the same rising interest in tackling bias, is betting that software can address some of training’s weaknesses usually for less money, so smaller companies can afford it.

As tantalizing as unconscious bias training is, it faces serious limits ones that companies might be choosing to ignore.

Google’s Welle admitted that the company’s unconscious bias training is more explanatory andNot very practical.” Google has built a second workshop that trains people to step in when they see biased interactions, but it’s just getting rolled out only about 5% of their employees have gone through it.

The central contradiction of hidden bias training is that you can’t train something you can’t control.

Google has been able to measure and show, using control groups, that Googlers who went through unconscious bias training felt more aware of unconscious bias and felt more motivated to stop it.