  Background: The use of Grey Literature (GL) has been investigate in diverse
research areas. In Software Engineering (SE), this topic has an increasing
interest over the last years. Problem: Even with the increase of GL published
in diverse sources, the understanding of their use on the SE research community
is still controversial. Objective: To understand how Brazilian SE researchers
use GL, we aimed to become aware of the criteria to assess the credibility of
their use, as well as the benefits and challenges. Method: We surveyed 76
active SE researchers participants of a flagship SE conference in Brazil, using
a questionnaire with 11 questions to share their views on the use of GL in the
context of SE research. We followed a qualitative approach to analyze open
questions. Results: We found that most surveyed researchers use GL mainly to
understand new topics. Our work identified new findings, including: 1) GL
sources used by SE researchers (e.g., blogs, community website); 2) motivations
to use (e.g., to understand problems and to complement research findings) or
reasons to avoid GL (e.g., lack of reliability, lack of scientific value); 3)
the benefit that is easy to access and read GL and the challenge of GL to have
its scientific value recognized; and 4) criteria to assess GL credibility,
showing the importance of the content owner to be renowned (e.g., renowned
author and institutions). Conclusions: Our findings contribute to form a body
of knowledge on the use of GL by SE researchers, by discussing novel (some
contradictory) results and providing a set of lessons learned to both SE
researchers and practitioners.
