What is PKV, Present Knowledge Value?

This website ranks currently noteworthy scientific and technological papers using an index called the Present Knowledge Value (PKV). By “currently noteworthy,” we mean “highly valuable at this very moment.” In other words, instead of highlighting long-standing, frequently cited “long-seller” papers that have been referenced over many years, the distinctive feature of this website is its focus on papers that have recently gained particular attention. As an indicator of present value, we have independently defined the Present Knowledge Value (PKV) and use this metric to showcase papers that are evaluated as having high current significance.

At present, the value of academic papers is often discussed in terms of citation counts and impact factors. A citation count refers to the number of times a paper has been cited by other papers. Being cited by another paper means that the authors of that paper have used it as a reference, and therefore, a frequently cited paper is considered to have high value. However, since only authors of other papers can cite it, citation counts do not reveal whether the paper is being used as a reference by people who do not write academic articles. In other words, even if practicing engineers do not consult a paper, as long as researchers cite it, the paper will accumulate many citations and thus be regarded as valuable.

The impact factor, on the other hand, is a metric that reflects the average number of citations received by papers published in a particular journal. Unlike citation counts, which are assigned to individual papers, the impact factor is assigned to journals. Nevertheless, because the impact factor is also based on citation counts, it shares the same limitation: it does not show how much a paper is being referenced by people outside the community of paper-writing researchers.

In contrast, the Present Knowledge Value (PKV) adopted by this website is calculated not from citation counts but from the number of times a paper has been accessed. Therefore, it stands apart from traditional indicators such as citation counts and impact factors, which only reflect the judgments of scholars who publish papers. The PKV changes depending on how many people from diverse professions—not just researchers—show interest in and access a paper. Thus, it can be regarded as a value indicator that reflects a broader range of perspectives.