Update README.md

README.md

@@ -33,7 +33,8 @@ The `ogbg-molhiv` dataset is a small molecular property prediction dataset, adap
 
 ### Supported Tasks and Leaderboards
 
-`ogbg-molhiv` should be used for molecular property prediction (aiming to predict whether molecules inhibit HIV or not), a binary classification task.
+`ogbg-molhiv` should be used for molecular property prediction (aiming to predict whether molecules inhibit HIV or not), a binary classification task. The score used is ROC-AUC.
+
 The associated leaderboards are here: [OGB leaderboard](https://ogb.stanford.edu/docs/leader_graphprop/#ogbg-molhiv) and [Papers with code leaderboard](https://paperswithcode.com/sota/graph-property-prediction-on-ogbg-molhiv).
 
 ## External Use