Update README.md

README.md

@@ -13,9 +13,15 @@ This is a dataset for Thai Coreference and Zero Pronoun Resolution.
 Raw textual data was retrieved from [Han-Coref](https://huggingface.co/pythainlp/han-coref-v1.0).
 The coreferece labels were re-annotate to include zero pronoun resolution to coreference resolution.
 
-### Annotators
+## Data Format
 
-<!-- This section describes the annotation process such as annotation tools used in the process, the amount of data annotated, annotation guidelines provided to the annotators, interannotator statistics, annotation validation, etc. -->
+The dataset contains 4 columns:
+ 1. **text**: Raw text data
+ 2. **clusters**: Coreference labels in nested list format. The outter list contains lists of clusters (coreference chains). Each cluster list contains start and end indexes pairs that are refer to the same entities.
+ 3. **mention_type**: Type of each start and end indexes pair in *clusters*.
+ 4. **clusters_strings**: String of each start and end indexes pair in *clusters*. 
+
+## Annotators
 
 The anotators are Thai native speakers who were not linguists. 
 The annotation process is divided into two steps: