diff --git a/PyCTBN/PyCTBN/utility/json_importer.py b/PyCTBN/PyCTBN/utility/json_importer.py
index edff212..2cadff4 100644
--- a/PyCTBN/PyCTBN/utility/json_importer.py
+++ b/PyCTBN/PyCTBN/utility/json_importer.py
@@ -49,10 +49,10 @@ class JsonImporter(AbstractImporter):
         super(JsonImporter, self).__init__(file_path)
         self._raw_data = self.read_json_file()
 
-    def import_data(self, indx: int) -> None:
+    def import_data(self, indx: int = 0) -> None:
         """Implements the abstract method of :class:`AbstractImporter`.
 
-        :param indx: the index of the outer JsonArray to extract the data from
+        :param indx: the index of the outer JsonArray to extract the data from, default to 0
         :type indx: int
         """
         self._array_indx = indx
@@ -101,7 +101,12 @@ class JsonImporter(AbstractImporter):
         """
         with open(self._file_path) as f:
             data = json.load(f)
-            return data
+
+            if (isinstance(data,list)):
+                return data
+            else:
+                return [data]
+         
 
     def one_level_normalizing(self, raw_data: typing.List, indx: int, key: str) -> pd.DataFrame:
         """Extracts the one-level nested data in the list ``raw_data`` at the index ``indx`` at the key ``key``.
diff --git a/PyCTBN/tests/utility/test_json_importer.py b/PyCTBN/tests/utility/test_json_importer.py
index 877805b..a4bb4c0 100644
--- a/PyCTBN/tests/utility/test_json_importer.py
+++ b/PyCTBN/tests/utility/test_json_importer.py
@@ -39,7 +39,7 @@ class TestJsonImporter(unittest.TestCase):
         path = os.getcwd()
         path = path + '/data.json'
         j1 = JsonImporter(path, '', '', '', '', '')
-        self.assertTrue(self.ordered(data_set) == self.ordered(j1._raw_data))
+        self.assertTrue(self.ordered([data_set]) == self.ordered(j1._raw_data))
         os.remove('data.json')
 
     def test_read_json_file_not_found(self):
@@ -155,7 +155,7 @@ class TestJsonImporter(unittest.TestCase):
         self.assertEqual(j1.file_path, "./PyCTBN/test_data/networks_and_trajectories_binary_data_01_3.json")
 
     def test_import_data(self):
-        j1 = JsonImporter("./PyCTBN/test_data/networks_and_trajectories_binary_data_01_3.json", 'samples', 'dyn.str', 'variables', 'Time', 'Name')
+        j1 = JsonImporter("./PyCTBN/test_data/networks_and_trajectories_binary_data_02_10_1.json", 'samples', 'dyn.str', 'variables', 'Time', 'Name')
         j1.import_data(0)
         self.assertEqual(list(j1.variables[j1._variables_key]),
                          list(j1.concatenated_samples.columns.values[1:len(j1.variables[j1._variables_key]) + 1]))