Employees commonly rest their discrimination cases on a showing that "similarly situated" coworkers were treated more favorably.  For example: an employee with an age discrimination claim might argue that he was disciplined for being late, while his younger coworkers were not.  That fact doesn't matter in court, however, unless he can show that the younger coworkers were "similarly situated" to him - i.e., that they all had the same work
responsibilities, supervisors, and the like.  Stated another way, the coworkers' infractions must have taken place  “under nearly identical circumstances.”

Today, the 5th Circuit issued an opinion re-affirming this standard:  Harvey Hoffman v. Baylor Healthcare System, Case No. 14-10258 (5th Cir., Jan. 6, 2015).  Mr. Hoffman sued his employer, claiming that he was fired because of his age.  Hoffman was employed as an MRI Technician, and he admitted that he “clearly had culpability in the breakdown of the MRI process." He claimed, however, that other younger employees were not held to the same standards that he was.  He identified to younger coworkers who got away with similar misconduct without being disciplined, and claimed they were "similarly situated" to him, except for the fact that they were younger.  The trial court dismissed his case, and the Fifth Circuit upheld the dismissal.  The problem was that the younger coworkers "did not share the same supervisor as
Hoffman," worked "in entirely different departments of the hospital," were not MRI Technicians, and thus "were not subject to the requirements of Hoffman’s job description," and unlike Hoffman, did not have discipline histories.  In short, the coworkers were "insufficiently similar" to support a claim of differential treatment.

This is a good lesson on the type of evidence necessary to support a claim of discrimination.  To show that you were treated less favorably than your coworkers, the coworkers you're comparing yourself to must be "similarly situated" to you.