add fields and file descriptions

README.md

@@ -86,11 +86,30 @@ English
 
 ### Data Fields
 
-[Needs More Information]
+The CSV files contain the following fields:
+
+| Field | Description |
+| ----- | ----------- |
+| `index` | (int) Index of the article in the current dataset |
+| `pmid` | (int) PubMed ID |
+| `doi` | (str) Digital Object Identifier |
+| `year` | (int) Year of publication (yyyy format)|
+| `journal_title` | (str) Title of the journal |
+| `journal_iso_abbreviation` | (str) ISO abbreviation of the journal |
+| `title` | (str) Title of the article |
+| `abstract` | (str) Abstract of the article |
+| `category` | (enum) Category of the article, either "CognitiveTask" or "CognitiveConstruct" |
+| `label` | (enum) Label of the article, which refers to the class labels in the `ontologies/efo.owl` ontology |
+| `original_index` | (int) Index of the article in the full dataset |
+
 
 ### Data Splits
 
-[Needs More Information]
+| Dataset | Description |
+| ------- | ----------- |
+| `pubmed/abstracts.csv.gz` | Full dataset |
+| `pubmed/abstracts20pct.csv.gz` | 20% of the dataset (stratified random sample by `label`) |
+| `gpt3/abstracts_gp3ada.nc` | GPT-3 embeddings of the entire dataset in XArray/CDF4 format, indexed by `doi` |
 
 ## Dataset Creation