[1] Though no PDPs have been formally and openly adopted by any governmental entity, there is significant work being done by scientists and nongovernmental organizations to develop cohesive plans of action to utilize in the event of detection.
The scale was designed by Iván Almár and Jill Tarter to help policy-makers formulate an initial judgment on a detection's potential consequences.
The formulation of a cohesive plan for a response to the detection of ETI would involve the development of scenario-contingent strategies for managing the discovery and its consequences.
Confirmation of such fossilized or living organisms on a nearby planet or moon could still have profound effects on individuals’ world-views and raise many ethical and practical issues.
[8] Regardless of the nature of a confirmed detection, PDPs also place considerable emphasis on the range of likely reactions from different constituencies, including the press, various religious groups, political leaders, and the general public.
Shortly after a confirmed detection, the timely application of relevant interdisciplinary data is likely to prove invaluable in implementing the appropriate policy as well as in the delivery of educational and public relations initiatives particular to the situation at hand.
Michaud posits that the more decipherable the information received from contact with ETI, the higher a chance there is for political reaction against alien cultural influences.
For instance, should a signal of ET origin be sufficiently ambiguous or otherwise difficult to interpret, the detecting party may perceive a need to withhold information about the discovery to prevent unintended reactions from the general public or other political entities.
However, in the absence of an intergovernmental agreement or structures for building consensus on the subject, nations, groups, businesses and individuals are free to act autonomously.
It is precisely because the process of sculpting a collective message would be slow and laborious (but intensely important), that most scientists recommend having a PDP with some prescribed action laid out before contact is made.
Due to the perceived risk of revealing the precise location of the Earth to alien civilizations, METI has been heavily criticized as irresponsible considering the lack of information available about any real or potential ETI threat.
Notable among the critics of METI were the (late) British theoretical physicist Stephen Hawking and includes science fiction author David Brin.
Aimed at the political leadership that would be in a decision-making role immediately following a confirmed detection, it describes, among other things, the circumstances under which it may or may not be advisable to withhold such information from the public.
As more of an analysis of fallout and pertinent considerations than an explicit PDP, the report does not specifically recommend a cover-up of evidence of extraterrestrial life.
The IAA, in an attempt to draw up universal guidelines on the immediate steps to be taken by the group or individual that makes a discovery, drafted the "Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence".