diff --git a/tests/test_transformer.py b/tests/test_transformer.py
index b1b5acd..3a0ddb9 100644
--- a/tests/test_transformer.py
+++ b/tests/test_transformer.py
@@ -57,19 +57,19 @@ def test_xmltransformer_iterates_successfully_if_get_optional_fields_returns_non
         assert len(output_records.deleted_records) == 1
 
 
-def test_xmltransformer__write_output_files_writes_timdex_records_and_deleted_files(
+def test_xmltransformer_transform_and_write_output_files_writes_output_files(
     tmp_path, oai_pmh_records
 ):
     output_file = str(tmp_path / "output_file.json")
     transformer = XmlTransformer("cool-repo", oai_pmh_records)
-    transformer._write_output_files(output_file)
+    transformer.transform_and_write_output_files(output_file)
     output_files = list(tmp_path.iterdir())
     assert len(output_files) == 2
     assert output_files[0].name == "output_file.json"
     assert output_files[1].name == "output_file.txt"
 
 
-def test_xmltransformer__write_output_files_no_deleted_records_file_if_not_needed(
+def test_xmltransformer_transform_and_write_output_files_no_txt_file_if_not_needed(
     tmp_path,
 ):
     output_file = str(tmp_path / "output_file.json")
@@ -77,7 +77,7 @@ def test_xmltransformer__write_output_files_no_deleted_records_file_if_not_neede
         "tests/fixtures/datacite/datacite_records.xml"
     )
     transformer = XmlTransformer("cool-repo", datacite_records)
-    transformer._write_output_files(output_file)
+    transformer.transform_and_write_output_files(output_file)
     assert len(list(tmp_path.iterdir())) == 1
     assert next(tmp_path.iterdir()).name == "output_file.json"
 
diff --git a/transmogrifier/cli.py b/transmogrifier/cli.py
index 13cd200..373f62d 100644
--- a/transmogrifier/cli.py
+++ b/transmogrifier/cli.py
@@ -41,7 +41,7 @@ def main(source, input_file, output_file, verbose):
     logger.info("Running transform for source %s", source)
 
     transformer = Transformer.load(source, input_file)
-    transformer._write_output_files(output_file)
+    transformer.transform_and_write_output_files(output_file)
     logger.info(
         (
             "Completed transform, total records processed: %d, "
diff --git a/transmogrifier/sources/transformer.py b/transmogrifier/sources/transformer.py
index 2044ef1..90eae10 100644
--- a/transmogrifier/sources/transformer.py
+++ b/transmogrifier/sources/transformer.py
@@ -70,8 +70,13 @@ def __next__(self) -> TimdexRecord:
                 continue
 
     @final
-    def _write_output_files(self, output_file: str) -> None:
-        self.write_timdex_records_to_json_file(output_file)
+    def transform_and_write_output_files(self, output_file: str) -> None:
+        """Iterates through source records to transform and write to output files.
+
+        Args:
+            output_file: The name of the output files.
+        """
+        self._write_timdex_records_to_json_file(output_file)
         if self.processed_record_count == 0:
             raise ValueError(
                 "No records processed from input file, needs investigation"
@@ -80,16 +85,17 @@ def _write_output_files(self, output_file: str) -> None:
             deleted_output_file = output_file.replace("index", "delete").replace(
                 "json", "txt"
             )
-            self.write_deleted_records_to_txt_file(deleted_records, deleted_output_file)
+            self._write_deleted_records_to_txt_file(
+                deleted_records, deleted_output_file
+            )
 
     @final
-    def write_timdex_records_to_json_file(self, output_file: str) -> int:
+    def _write_timdex_records_to_json_file(self, output_file: str) -> int:
         """
         Write TIMDEX records to JSON file.
 
         Args:
             output_file: The JSON file used for writing TIMDEX records.
-
         """
         count = 0
         try:
@@ -121,10 +127,16 @@ def write_timdex_records_to_json_file(self, output_file: str) -> int:
 
     @final
     @staticmethod
-    def write_deleted_records_to_txt_file(
-        deleted_records: list[str], output_file_path: str
+    def _write_deleted_records_to_txt_file(
+        deleted_records: list[str], output_file: str
     ):
-        with open(output_file_path, "w") as file:
+        """Write deleted records to the specified text file.
+
+        Args:
+            deleted_records: The deleted records to write to file.
+            output_file: The text file used for writing deleted records.
+        """
+        with open(output_file, "w") as file:
             for record_id in deleted_records:
                 file.write(f"{record_id}\n")
 
@@ -232,6 +244,7 @@ def get_required_fields(self, source_record: JSON | Tag) -> dict:
         pass
 
     @classmethod
+    @abstractmethod
     def get_main_titles(cls, source_record: JSON | Tag) -> list[str]:
         """
         Retrieve main title(s) from an source record.
@@ -241,7 +254,7 @@ def get_main_titles(cls, source_record: JSON | Tag) -> list[str]:
         Args:
             source_record: A single source record.
         """
-        return []
+        pass
 
     @classmethod
     @abstractmethod