That's a really long answer to give, but as I noted, the factors you mentioned indicate unreliable, potentially biased research. In the absence of those and the presence of a properly applied, ethically administered scientific process, one gets good data.

There are certainly extensive, rigorous, lengthy standards for creating credible research, but entire courses are devoted to those. Some good reading on how to conduct and recognize it can be found online, and it's important to vet the research-

look for neutrality, appropriate funding sources, useful sample sizes or combination of smaller samples in solid meta-analyses, awareness of variables/controls, proper duration, subject choice, goodness, a long list, but indeed, it's not just a random abstract concept to brush away with concerns over imperfections.

Don't throw baby out with bath water.

"How do you know it when you see it?"

I personally know it when I see it because I devoted about 4 years to becoming a good secondary researcher and writing about my findings, and I suppose my studies in critical thinking, psychology and such helped.