diff --git a/src/Dataset.py b/src/Dataset.py
index 48d6ee542fe89aa4811be6321cd964cf0275b2b8..e8f0314352d22230d893d1bcb0eb551c9e3d36a5 100644
--- a/src/Dataset.py
+++ b/src/Dataset.py
@@ -23,7 +23,18 @@ class Dataset:
         # more preprocessing goes here
         return dataframe
 
-    def get_combined_anxiety_score(self, dataframe: pd.DataFrame):
+    def get_combined_anxiety_score(self, dataframe: pd.DataFrame) -> pd.Series:
+        """Get the combined axiety score, as a column.
+        This score is based on the GAN, SPIN and SWL metrics.
+        Each of the three columns are first normalised,
+          then the mean is returned.
+
+        Args:
+            dataframe (pd.DataFrame): the dataframe.
+
+        Returns:
+            pd.Series: the anxiety score column.
+        """
         gad_max = 21
         gad_min = 0
         gad_normalised = (dataframe["GAD_T"] - gad_min) / gad_max