diff --git a/burr/core/typing.py b/burr/core/typing.py
index 6fa4bae2c..87e2040af 100644
--- a/burr/core/typing.py
+++ b/burr/core/typing.py
@@ -26,11 +26,6 @@
 if TYPE_CHECKING:
     from burr.core import Action, Graph, State
 
-try:
-    from typing import Self
-except ImportError:
-    Self = "TypingSystem"
-
 
 class TypingSystem(abc.ABC, Generic[BaseType]):
     @abc.abstractmethod
@@ -115,15 +110,15 @@ class ActionSchema(
     """
 
     @abc.abstractmethod
-    def state_input_type() -> Type[StateInputType]:
+    def state_input_type(self) -> Type[StateInputType]:
         pass
 
     @abc.abstractmethod
-    def state_output_type() -> Type[StateOutputType]:
+    def state_output_type(self) -> Type[StateOutputType]:
         pass
 
     @abc.abstractmethod
-    def intermediate_result_type() -> Type[IntermediateResultType]:
+    def intermediate_result_type(self) -> Type[IntermediateResultType]:
         pass
 
 
@@ -144,4 +139,7 @@ def construct_data(self, state: State[dict]) -> dict:
         return state.get_all()
 
     def construct_state(self, data: dict) -> State[dict]:
+        # imported here to avoid a circular import -- state.py imports this module
+        from burr.core.state import State
+
         return State(data, typing_system=self)
diff --git a/tests/core/test_typing.py b/tests/core/test_typing.py
new file mode 100644
index 000000000..33d87ab24
--- /dev/null
+++ b/tests/core/test_typing.py
@@ -0,0 +1,67 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+import pytest
+
+from burr.core.action import DEFAULT_SCHEMA
+from burr.core.state import State
+from burr.core.typing import ActionSchema, DictBasedTypingSystem
+
+
+def test_action_schema_subclass_implements_instance_methods():
+    class MySchema(ActionSchema[State, State, dict]):
+        def state_input_type(self) -> type[State]:
+            return State
+
+        def state_output_type(self) -> type[State]:
+            return State
+
+        def intermediate_result_type(self) -> type[dict]:
+            return dict
+
+    schema = MySchema()
+    assert schema.state_input_type() is State
+    assert schema.state_output_type() is State
+    assert schema.intermediate_result_type() is dict
+
+
+def test_action_schema_incomplete_subclass_cannot_instantiate():
+    class Incomplete(ActionSchema):
+        def state_input_type(self) -> type[State]:
+            return State
+
+    with pytest.raises(TypeError):
+        Incomplete()
+
+
+def test_default_schema_satisfies_action_schema():
+    assert isinstance(DEFAULT_SCHEMA, ActionSchema)
+    assert DEFAULT_SCHEMA.intermediate_result_type() is dict
+    with pytest.raises(NotImplementedError):
+        DEFAULT_SCHEMA.state_input_type()
+    with pytest.raises(NotImplementedError):
+        DEFAULT_SCHEMA.state_output_type()
+
+
+def test_dict_based_typing_system():
+    typing_system = DictBasedTypingSystem()
+    assert typing_system.state_type() is dict
+    assert typing_system.state_pre_action_run_type(None, None) is dict
+    assert typing_system.state_post_action_run_type(None, None) is dict
+    state = typing_system.construct_state({"a": 1})
+    assert isinstance(state, State)
+    assert typing_system.construct_data(state) == {"a": 1}