(Un)conventional combinations: At the origins of breakthrough inventions

Impactful inventions carry forward combinations of components which depart from common practices: they remove restrictions in the knowledge space by breaking conventional rules. In this paper we present a novel measure of the extent to which combinations in the inventive process conform to established practices. We borrow an established approach from the literature on product market diversification and adapt it to measure how combinations are typical or unconventional. We find that most of the inventive activities are grounded in conventional efforts, with rare instances of unconventional connections. Unconventionality is more likely to occur with experience, in teams and in large organizations. Moreover, patents which cite a widespread spectrum of previous results have a higher chance to identify unconventional connections. We also observe that inventions carrying forward unconventional combinations are cited more by future patent applications than conventional inventions.