Final answer:
The highest quality and most reliable audit evidence that segregation of duties is properly implemented is obtained through audit studies.
Step-by-step explanation:
The highest quality and most reliable audit evidence that segregation of duties is properly implemented is obtained through audit studies. Audit studies are experiments that are used to gather evidence about discrimination in various areas, including education, housing, the labor market, and the criminal justice system.
They are considered the most effective method for determining cause and effect, although they can be challenging to implement and more expensive than analyzing existing data with multiple regression models.