  Rule learning approaches for knowledge graph completion are efficient,
interpretable and competitive to purely neural models. The rule aggregation
problem is concerned with finding one plausibility score for a candidate fact
which was simultaneously predicted by multiple rules. Although the problem is
ubiquitous, as data-driven rule learning can result in noisy and large
rulesets, it is underrepresented in the literature and its theoretical
foundations have not been studied before in this context. In this work, we
demonstrate that existing aggregation approaches can be expressed as marginal
inference operations over the predicting rules. In particular, we show that the
common Max-aggregation strategy, which scores candidates based on the rule with
the highest confidence, has a probabilistic interpretation. Finally, we propose
an efficient and overlooked baseline which combines the previous strategies and
is competitive to computationally more expensive approaches.
