This paper examines and deconstructs the Rio Scale, focusing primarily on the recently published Rio Scale 2.0 concept, from the perspective of a social scientist. I argue that although there is value in developing tools to help astronomers and other scientists communicate their perceptions about the significance of a contact event to the media and the general public, the Rio Scale 2.0 remains problematic conceptually and, thus, does not represent a robust method for assessing or communicating the import of a valid contact. Therefore, it should not be used as a method for informing the media or the general public about scenarios that involve the detection of valid signals suggesting the existence of extraterrestrial intelligence.

The Rio scale is a tool for communicating the significance of a signal to the general public. It assigns scores to signals detected in searches for extraterrestrial intelligence (SETI), which characterizes both the consequences of a signal and the probability the signal is truly from ETI, in an easily digestible format for laypeople to interpret. In the 17 years since its construction, the number of groups actively conducting searches for evidence of intelligent life beyond the Earth has increased significantly, and theoretical work has established a new suite of observables that are capable of revealing the presence of ETI in a range of astronomical observations. In this paper, we revise the Rio scale, with the aim of (i) achieving consensus across academic disciplines on a scheme for classifying signals potentially indicating the existence of advanced extraterrestrial life, (ii) supplying a pedagogical tool to help inform the public about the process scientists go through to develop an understanding of a signal and (iii) providing a means of calibrating the expectations of the world at large when signals are discussed in the media. We also present (and encourage the SETI community to adopt) a single set of consistent terminology for discussing signals.