diff --git a/ARCtrl.sln b/ARCtrl.sln
index 784d5053..c5527abb 100644
--- a/ARCtrl.sln
+++ b/ARCtrl.sln
@@ -67,6 +67,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Python", "Python", "{501F6D
 	ProjectSection(SolutionItems) = preProject
 		tests\Python\test_index.py = tests\Python\test_index.py
 		tests\Python\test_JsonController.py = tests\Python\test_JsonController.py
+		tests\Python\test_OntologyAnnotation.py = tests\Python\test_OntologyAnnotation.py
 		tests\Python\test_XlsxController.py = tests\Python\test_XlsxController.py
 	EndProjectSection
 EndProject
diff --git a/src/Core/ArcTypes.fs b/src/Core/ArcTypes.fs
index c7923537..4f68e34d 100644
--- a/src/Core/ArcTypes.fs
+++ b/src/Core/ArcTypes.fs
@@ -998,6 +998,34 @@ type ArcStudy(identifier : string, ?title, ?description, ?submissionDate, ?publi
     /// <param name="other">The other ArcStudy to test for reference.</param>
     member this.ReferenceEquals (other: ArcStudy) = System.Object.ReferenceEquals(this,other)
 
+    // Use this for better print debugging and better unit test output
+    override this.ToString() =
+        sprintf 
+            """ArcStudy {
+    Identifier = %A,
+    Title = %A,
+    Description = %A,
+    SubmissionDate = %A,
+    PublicReleaseDate = %A,
+    Publications = %A,
+    Contacts = %A,
+    StudyDesignDescriptors = %A,
+    Tables = %A,
+    RegisteredAssayIdentifiers = %A,
+    Comments = %A,
+}"""
+            this.Identifier
+            this.Title
+            this.Description
+            this.SubmissionDate
+            this.PublicReleaseDate
+            this.Publications
+            this.Contacts
+            this.StudyDesignDescriptors
+            this.Tables
+            this.RegisteredAssayIdentifiers
+            this.Comments
+
     // custom check
     override this.Equals other =
         match other with
@@ -1744,7 +1772,39 @@ type ArcInvestigation(identifier : string, ?title : string, ?description : strin
     /// If true, updating one will update the other due to mutability.
     /// </summary>
     /// <param name="other">The other ArcInvestigation to test for reference.</param>
-    member this.ReferenceEquals (other: ArcStudy) = System.Object.ReferenceEquals(this,other)
+    member this.ReferenceEquals (other: ArcInvestigation) = System.Object.ReferenceEquals(this,other)
+
+    // Use this for better print debugging and better unit test output
+    override this.ToString() =
+        sprintf 
+            """ArcStudy {
+    Identifier = %A,
+    Title = %A,
+    Description = %A,
+    SubmissionDate = %A,
+    PublicReleaseDate = %A,
+    OntologySourceReferences = %A,
+    Publications = %A,
+    Contacts = %A,
+    Assays = %A,
+    Studies = %A,
+    RegisteredStudyIdentifiers = %A,
+    Comments = %A,
+    Remarks = %A,
+}"""
+            this.Identifier
+            this.Title
+            this.Description
+            this.SubmissionDate
+            this.PublicReleaseDate
+            this.OntologySourceReferences
+            this.Publications
+            this.Contacts
+            this.Assays
+            this.Studies
+            this.RegisteredStudyIdentifiers
+            this.Comments
+            this.Remarks
 
     // custom check
     override this.Equals other =
diff --git a/tests/Python/test_OntologyAnnotation.py b/tests/Python/test_OntologyAnnotation.py
new file mode 100644
index 00000000..b0ff62c3
--- /dev/null
+++ b/tests/Python/test_OntologyAnnotation.py
@@ -0,0 +1,8 @@
+from .ARCtrl.arctrl import OntologyAnnotation, JsonController, ArcInvestigation
+
+class TestOntologyAnnotation:
+      
+    def test_create(self):
+        oa = OntologyAnnotation("instrument model", "MS", "MS:1234567")
+        assert oa.NameText == "instrument model"
+        
\ No newline at end of file