Drop ref to stratified splitting.

Author: MarkDaoust

site/en/tutorials/structured_data/imbalanced_data.ipynb

@@ -297,7 +297,7 @@
         "id": "8a_Z_kBmr7Oh"
       },
       "source": [
-        "Given the small number of positive labels, this seems about right. In case the average class probability deviates by a large amount, one could use a stratified splitting scheme.\n",
+        "Given the small number of positive labels, this seems about right.\n",
         "\n",
         "Normalize the input features using the sklearn StandardScaler.\n",
         "This will set the mean to 0 and standard deviation to 1.\n",