Plagiarism and credible sources Plagiarism is the reuse of other's materials without proper credit and acknowledgement [1]
Credible sources are vaguely defined, but it can be attributed to verifiable facts in the literature [2]
I want to ask that, in a situation, when an academician found an &quot;inspiring&quot; idea (not necessarily well-defined) on the non-academic part of the Internet, such as some blogs, or discussion on the social networks, a Youtube video, or some crude Python scripts, etc, and work out on their own to shape up an explicit scientific study or, for example, write up a sophisticated numerical package, then two there are two things here: (1) the source does not provide a scientific study, nor in an academic form, thus it cannot be considered as &quot;credible source&quot;, so usually it cannot be cited, (2) but it provides a crude idea that one formulates a scientific problem based on it, so not citing it should be considered as plagiarism.
What is the way to deal with it? Whether to cite or not to cite? For a casual discussion on the Internet to inspire research might be rare in reality, at least it is me who hasn't seen a case, but what if this situation came into reality?
I'm not sure where you heard that you should only cite &quot;credible&quot; sources. Credibility is a judgement call, best avoided. You should always cite things that you have found and used, even if they were ill formed when found. The ideas are those of others that you have developed further. But the idea didn't originate with you, so you are open to charges of plagiarism if you don't cite. The likelihood of a formal charge may be slim, but other academics might doubt you if you cut corners.
That doesn't, however, mean that you have to accept the veracity of the things you cite. In fact, you can, and in some cases should, discuss the doubts you have or the ill state in which you found a resource that you use.
I'll note that in mathematics, we sometimes have to cite papers that contain serious errors so that we can correct those errors. But our work is still based on the work of the earlier mathematicians, even if we correct it.