A strength is that it is supported by findings from Bickmanās field experiment. In Bickmanās study, researchers dressed as a guard, a milkman, or in plain clothes and asked members of the public to complete tasks, such as picking up litter. Bickman found that people were twice as likely to obey when the researcher wore a guardās uniform compared to plain clothes, suggesting that uniforms are a symbol of authority, increasing obedience. This supports Milgramās finding that uniform is a powerful situational variable influencing obedience, as it lends legitimacy and authority.