Update README.md

README.md

@@ -118,15 +118,17 @@ An example of 'train' looks as follows:
 ### Data Fields
 The data fields are the same among all splits.
 
-- `id`: the instance id of this sentence
-- `token`: the list of tokens of this sentence, obtained with the StanfordNLP toolkit.
-- `relation`: the relation label of this instance.
-- `subj_start`: the 0-based index of the start token of the relation subject mention.
-- `subj_end`: the 0-based index of the end token of the relation subject mention, exclusive.
-- `subj_type`: the NER type of the subject mention, among 23 fine-grained types used in the [Stanford NER system](https://stanfordnlp.github.io/CoreNLP/ner.html).
-- `obj_start`: the 0-based index of the start token of the relation object mention.
-- `obj_end`: the 0-based index of the end token of the relation object mention, exclusive.
-- `obj_type`: the NER type of the object mention, among 23 fine-grained types used in the [Stanford NER system](https://stanfordnlp.github.io/CoreNLP/ner.html).
+
+- `id`: the instance id of this sentence, a `string` feature.
+- `docid`: the TAC KBP document id of this sentence, a `string` feature.
+- `token`: the list of tokens of this sentence, obtained with the StanfordNLP toolkit, a `list` of `string` features.
+- `relation`: the relation label of this instance, a `string` classification label.
+- `subj_start`: the 0-based index of the start token of the relation subject mention, an `ìnt` feature.
+- `subj_end`: the 0-based index of the end token of the relation subject mention, exclusive, an `ìnt` feature.
+- `subj_type`: the NER type of the subject mention, among 23 fine-grained types used in the [Stanford NER system](https://stanfordnlp.github.io/CoreNLP/ner.html), a `string` feature.
+- `obj_start`: the 0-based index of the start token of the relation object mention, an `ìnt` feature.
+- `obj_end`: the 0-based index of the end token of the relation object mention, exclusive, an `ìnt` feature.
+- `obj_type`: the NER type of the object mention, among 23 fine-grained types used in the [Stanford NER system](https://stanfordnlp.github.io/CoreNLP/ner.html), a `string` feature.
 ### Data Splits
 To miminize dataset bias, TACRED is stratified across years in which the TAC KBP challenge was run.
 Languages statistics for the splits differ because not all instances could be translated with the