Table 1.

Baseline strategies mitigate bias inconsistently.

	Bias mitigation strategy
Bias	TWAD	VPT	TWIX (ours)
Underskilling	↓ 3.7%	↓ 7.7%	↓ 3.0%
Overskilling	↑ 6.7%	↑ 7.0%	↓ 4.0%

We report the change in the AI system’s bias (negative percent change in worst-case performance) averaged across the surgeon groups as a result of adopting distinct mitigation strategies. An improvement in the worst-case performance corresponds to a reduction in bias. Results are shown for the needle handling skill assessment system deployed on data from USC. TWAD involves training an AI system with additional data, and VPT involves pre-training the AI system with surgical videos (see Methods).