According to Daniel Lakens, experimental psychologist at the Human-Technology Interaction group at Eindhoven University of Technology, The Netherlands who has tried to measure blogs and journal article on some dimension.
Blogs, on average, score better on some core scientific values, such as open data and code, transparency of the peer review process, egalitarianism, error correction, and open access. It is clear blogs impact the way we think and how science works. There is no intrinsic reason why blogs should have higher scientific quality than journal articles. It’s just that the authors of most blogs I read put some core scientific values into practice to a greater extent than editorial boards at journals.
Read his argument at