An annotation assistant for semi-automatic creation of annotated machine learning training data comprises a graphical annotation interface provider that provides a graphical annotation interface for displaying a sequence of tokens to be annotated and allowing a span selection by a user. An automatic span tagger comprises an artificial neural network configured to assign class probabilities to the tokens of the sequence of tokens and a processor-based path-scoring algorithm for computing scores for semantic attribute paths of the span selection. The graphical annotation interface is further configured for displaying the scored semantic attribute paths, and for receiving a selection among the scored semantic attribute paths from the user.