Fig. 2From: Deep learning-enabled natural language processing to identify directional pharmacokinetic drug–drug interactionsTraining and validation procedure. 325 and 81 FDA labels prespecified by TAC DDI 2019 [8] were used for model training and validation, respectively. These labels were provided as Structured Product Labeling (SPL) documents as XML files. Sentences were extracted from the XML files and re-annotated to fit the purpose of the two steps of our model (DDI relation extraction to identify PK DDI sentences, and precipitant/object entity recognition in those sentences). This training/validation procedure was applied twice, each for one step of the modelBack to article page