  Background: Blog posts are frequently used by software practitioners to share
information about their practice. Blog posts therefore provide a potential
source of evidence for software engineering (SE) research. The use of blog
posts as evidence for research appears contentious amongst some SE researchers.
Objective: To better understand the actual and perceived value of blog posts as
evidence for SE research, and to develop guidance for SE researchers on the use
of blog posts as evidence. Method: We further analyse responses from a
previously conducted attitudinal survey of 44 software engineering researchers.
We conduct a heatmap analysis, simple statistical analysis, and a thematic
analysis. Results: We find no clear consensus from respondents on researchers'
attitudes to the credibility of blog posts, or on a standard set of criteria to
evaluate blog-post credibility. We show that some of the responses to the
survey exhibit characteristics similar to the content of blog posts, e.g.,
asserting prior beliefs as claims, with no citations and little supporting
rationale. We illustrate our insights with ~60 qualitative examples from the
survey ~40% of the total responses. We complement our quantitative and
qualitative analyses with preliminary checklists to guide SE researchers.
Conclusion: Blog posts are relevant to research because they are written by
software practitioners describing their practice and experience. But evaluating
the credibility of blog posts, so as to select the higher-quality content,
remains an ongoing challenge. The quantitative and qualitative results, with
the proposed checklists, are intended to stimulate reflection and action in the
research community on the role of blog posts as evidence in software
engineering research. Finally, our findings on researchers' attitudes to blog
posts also provide more general insights into researchers' values for SE
research.
