  The purpose of this paper is to provide a review of the literature on the
original disruption index (DI1) and its variants in scientometrics. The DI1 has
received much media attention and prompted a public debate about science policy
implications, since a study published in Nature found that papers in all
disciplines and patents are becoming less disruptive over time. This review
explains in the first part the DI1 and its variants in detail by examining
their technicaland theoretical properties. The remaining parts of the review
are devoted to studies that examine the validity and the limitations of the
indices. Particular focus is placed on (1) possible biases that affect
disruption indices (2) the convergent and predictive validity of disruption
scores, and (3) the comparative performance of the DI1 and its variants. The
review shows that, while the literature on convergent validity is not entirely
conclusive, it is clear that some modified index variants, in particular DI5,
show higher degrees of convergent validity than DI1. The literature draws
attention to the fact that (some) disruption indices suffer from inconsistency,
time-sensitive biases, and several data-induced biases. The limitations of
disruption indices are highlighted and best practice guidelines are provided.
The review encourages users of the index to inform about the variety of DI1
variants and to apply the most appropriate variant. More research on the
validity of disruption scores as well as a more precise understanding of
disruption as a theoretical construct is needed before the indices can be used
in the research evaluation practice.
