diff --git a/quapy/data/_lequa.py b/quapy/data/_lequa.py
index e162f4c..7e4cf52 100644
--- a/quapy/data/_lequa.py
+++ b/quapy/data/_lequa.py
@@ -99,6 +99,9 @@ class SamplesFromDir(AbstractProtocol):
             sample, _ = self.load_fn(os.path.join(self.path_dir, f'{id}.txt'))
             yield sample, prevalence
 
+    def total(self):
+        return len(self.true_prevs)
+
 
 class LabelledCollectionsFromDir(AbstractProtocol):
 
@@ -113,6 +116,10 @@ class LabelledCollectionsFromDir(AbstractProtocol):
             lc = LabelledCollection.load(path=collection_path, loader_func=self.load_fn)
             yield lc
 
+    def total(self):
+        return len(self.true_prevs)
+
+
 
 class ResultSubmission: