Duty to find employment or comparable employment after employment termination?

What is the standard? Here are two attorneys with differing opinions:

Concerning a workers compensation claim:...In addition, you should start keeping a daily log, in a spiral bound notebook, of all the job searches you undercut after you have been fired. This is important because after you are fired, you have a duty to "mitigate" your damages. This means that you have a duty to go and look for other work. If you do not, you may be precluded from obtaining recovery of money damages for lost wages. This does not mean that you have to be successful, but you have to show that you have been diligent in seeking other employment.

In ADA case: Back Pay
This is the most common form of relief.
Includes the value of wages, salary, and fringe benefits the claimant would have received during the period of discrimination from the date of termination/failure to promote to the date of trial or settlement.
You have a duty to mitigate these damages by taking reasonable efforts to find comparable employment after you have been terminated.