An adverse action is an action taken to try to keep someone from opposing a discriminatory practice, or from participating in an employment discrimination proceeding. Examples of adverse actions include: employment actions such as termination, refusal to hire, and denial of promotion, other actions affecting employment such as threats, unjustified negative evaluations, unjustified negative references, or increased surveillance, and any other action such as an assault or unfounded civil or criminal charges that are likely to stop reasonable people from pursuing their rights.
Protected activity is any activity that opposed discrimination. Protected activity includes: opposition to a practice believed to be unlawful discrimination (opposition is informing an employer that you believe that he/she is engaging in prohibited discrimination.) Opposition is protected from retaliation as long as it is based on a reasonable, good-faith belief that the complained of practice violates anti-discrimination law; and the manner of the opposition is reasonable.
Examples of protected opposition include: complaining to anyone about alleged discrimination against oneself or others, threatening to file a charge of discrimination, picketing in opposition to discrimination, or refusing to obey an order reasonably believed to be discriminatory.
If you file a complaint of retaliation, one of the questions an investigator will as is if there is evidence raising an inference that retaliation was the cause of any adverse action?
An investigator will to to see if any adverse actions took place shortly after an employee engaged in any sort of protected activity AND will try to determine if the decision-maker knew that the complaining employee engaged in the protected activity before they made their decision on any adverse actions.
In other words, did your supervisor know you were complaining of discrimination before that supervisor refused to promote you or terminated you?
An investigator will also look to see if there was a long period of time between the protected activity and the adverse action, and will try to determine whether there is other evidence raising an inference that the cause of the adverse action was retaliation.
In other words, the investigator will look at the timing of your complaint of discrimination or you saying that you would file a complaint of discrimination, etc. compared to how long it was before you were denied a promotion or terminated (the adverse action).