However, customer input into evaluations may be seen as violating procedural justice. Employees may feel that customer evaluations are biased and that, in some cases, negative customer encounters are more the fault of the customer than the service provider. In the restaurant industry, other characteristics besides performance may come into patrons' evaluations of wait staff. For example, the ethnicity and gender of the server played a role in how positively they are evaluated as does the quality and price of the food, factors unrelated to the server's behavior and therefore leading to seeing customer evaluations as unfair.