In the context of employment discrimination laws, which of the following does NOT constitute discrimination?

Evaluating employees based on performance metrics does not constitute discrimination because it is a standard practice rooted in objective measurement of an employee's job performance, capabilities, and achievements. Performance evaluations are essential for ensuring that all employees are assessed fairly based on their contributions to the organization, rather than subjective factors such as race, gender, or personal relationships. This practice promotes a fair workplace where promotions and raises can be aligned with individual merit rather than discriminatory biases.

In contrast, hiring an employee regardless of race represents affirmative action to prevent discrimination, while providing equal pay for equal work ensures that all employees receive compensation based on their job functions, devoid of bias. Firing based on a personal vendetta, however, does involve unfair treatment and personal bias, which constitutes discriminatory behavior. Therefore, employing performance metrics as the basis for employee evaluation is a justifiable and non-discriminatory practice within employment law.