Make acc_norm a separate metric

lm_eval/base.py

@@ -225,22 +225,25 @@ class MultipleChoiceTask(Task):
     def process_results(self, doc, results):
         gold = doc["gold"]
 
+        acc = 1. if np.argmax(results) == gold else 0.
         completion_len = np.array([float(len(i)) for i in doc["choices"]])
-
-        acc = 1. if np.argmax(results/completion_len) == gold else 0.
+        acc_norm = 1. if np.argmax(results / completion_len) == gold else 0.
 
         return {
-            "acc": acc
+            "acc": acc,
+            "acc_norm": acc_norm,
         }
     
     def higher_is_better(self):
         return {
-            "acc": True
+            "acc": True,
+            "acc_norm": True,
         }
     
     def aggregation(self):
         return {
-            "acc": mean
+            "acc": mean,
+            "acc_norm": mean,
         }