“…For some relations, even when considering only sentences with entities of the relevant types, the ratio between positive and negative examples is highly skewed toward the latter and obtaining a modest amount of positive examples will require a laborious annotation effort (see §3). While manual annotation of large datasets is a viable approach, it typically requires contracting a team of professional annotators (Doddington et al, 2004;Ellis et al, 2015) or crowd workers (Zhang et al, 2017;Yao et al, 2019) and is not well suited for smaller projects or for ad-hoc extraction tasks.…”