Irreproducible research and a typology of replication efforts.

The scholarly and scientific literature does not automatically correct itself. Erroneous findings may persist without correction or retraction. Following prior definitions of zombie articles that are retracted but continue to be cited affirmatively, we add another category of 'undead' articles. We define 'vampire' articles by two jointly necessary conditions. The first condition is irreproducibility, demonstrated by one or more failed efforts at replication or conditions that make replication impossible. We offer a novel typology of four categories of replication efforts. We propose a rule of thumb for how many failed efforts at replication might be required for each type of replication effort before the original finding is deemed irreproducible. The second necessary condition for a putative vampire article is that it is cited affirmatively in public policy, the scholarly literature, or private (neither governmental, nor published in the peer-reviewed scholarly literature) communications, after the first condition is met. We discuss rules of thumb for how many such affirmative citations might lead qualified researchers in that subfield to propose correction, retraction, or editorial note of concern for the article in question. Our first case concerns aerial shooting at coyotes and the second case predicted over-fishing. We discuss the damaging effects of vampire articles and why the metaphor has heuristic value and utility. Perhaps the current retraction guidelines could be sharpened to include considerations around vampire articles. We also discuss lessons from the communication sciences about how to remedy misinformation, offering recommendations to researchers, publishers and editors who are concerned with correcting their literatures and public trust in science generally.