diff --git a/flight/learning/torch/utils.py b/flight/learning/torch/utils.py
index 2816250..91c2b66 100644
--- a/flight/learning/torch/utils.py
+++ b/flight/learning/torch/utils.py
@@ -20,6 +20,10 @@
     from flight.learning.types import Data, FloatDouble, FloatTriple
 
 
+IID: t.Final[float] = 1e5
+NON_IID: t.Final[float] = 1e-5
+
+
 class FederatedDataModule(TorchDataModule):
     """
     This class defines a DataModule that is split across worker nodes in a federation's
@@ -177,8 +181,8 @@ def federated_split(
     topo: Topology,
     data: Data,
     num_labels: int,
-    label_alpha: float,
-    sample_alpha: float,
+    label_alpha: float = IID,
+    sample_alpha: float = IID,
     train_test_valid_split: FloatTriple | FloatDouble | None = None,
     ensure_at_least_one_sample: bool = True,
     rng: np.random.Generator | int | None = None,
diff --git a/tests/test_commons.py b/tests/test_commons.py
index ad9dc4a..1f3b777 100644
--- a/tests/test_commons.py
+++ b/tests/test_commons.py
@@ -3,24 +3,26 @@
 from flight.commons import proportion_split
 
 
-class TestProportionSplit:
-    def test_valid_proportions(self):
-        lst = list(range(10))
-        assert proportion_split(lst, (0.5, 0.5)) == ([0, 1, 2, 3, 4], [5, 6, 7, 8, 9])
-        assert proportion_split(lst, (0.5, 0.2, 0.3)) == (
-            [0, 1, 2, 3, 4],
-            [5, 6],
-            [7, 8, 9],
-        )
-
-    def test_proportions_sum_not_one(self):
-        with pytest.raises(ValueError):
-            proportion_split([1, 2, 3], (0.5, 0.6))
-
-    def test_negative_proportions(self):
-        with pytest.raises(ValueError):
-            proportion_split([1, 2, 3], (-0.5, 1.5))
-
-    def test_more_proportions_than_elements(self):
-        with pytest.raises(ValueError):
-            proportion_split([1, 2], (0.5, 0.5, 0.5))
+def test_valid_proportions():
+    lst = list(range(10))
+    assert proportion_split(lst, (0.5, 0.5)) == ([0, 1, 2, 3, 4], [5, 6, 7, 8, 9])
+    assert proportion_split(lst, (0.5, 0.2, 0.3)) == (
+        [0, 1, 2, 3, 4],
+        [5, 6],
+        [7, 8, 9],
+    )
+
+
+def test_proportions_sum_not_one():
+    with pytest.raises(ValueError):
+        proportion_split([1, 2, 3], (0.5, 0.6))
+
+
+def test_negative_proportions():
+    with pytest.raises(ValueError):
+        proportion_split([1, 2, 3], (-0.5, 1.5))
+
+
+def test_more_proportions_than_elements():
+    with pytest.raises(ValueError):
+        proportion_split([1, 2], (0.5, 0.5, 0.5))