In addition, many of the non-lexical feature classes, including those that have been identified as indicative of segment boundaries in previous work (e.g., prosody) and those that we hypothesized as good predictors of segment boundaries (e.g., motion, context), are not beneficial for recognizing boundaries when used in isolation.
these non-lexical features are useful when combined with lexical features, as the presence of the non-lexical features can balance the tendency of models trained with lexical cues alone to overpredict.