Is journal impact factor a good measure of research quality?

Impact factor is a journal-level average: citations to a journal's recent articles divided by the number of articles. Two things make it useless for judging an individual paper. First, citations within a journal are extremely skewed — a small fraction of articles earns most of them, so the average describes almost no real paper (Seglen 1997; Larivière et al. 2016). Second, the metric was designed in the 1960s to help librarians choose subscriptions, not to assess research; using it on a single article applies the wrong instrument (Seglen 1997; Nature Index). This is why thousands of institutions have signed DORA, which calls explicitly for ending journal-metric proxies in the evaluation of individual research. Quality is a property of the paper, so it has to be measured at the paper — which is what Nabu does, blind to the journal.