diff --git a/tests/test_adif.py b/tests/test_adif.py
index 032428e..e007ac9 100644
--- a/tests/test_adif.py
+++ b/tests/test_adif.py
@@ -23,7 +23,7 @@ from pyqso.adif import *
 
 class TestADIF(unittest.TestCase):
 
-    """ The unit tests for the ADIF module. """
+    """ The unit tests for the ADIF class. """
 
     def setUp(self):
         """ Set up the ADIF object needed for the unit tests. """
diff --git a/tests/test_awards.py b/tests/test_awards.py
index 4eaa85f..a7ecf0e 100644
--- a/tests/test_awards.py
+++ b/tests/test_awards.py
@@ -42,10 +42,6 @@ class TestAwards(unittest.TestCase):
         self.logbook.logs = self.logbook.get_logs()
         assert(self.logbook.logs is not None)
 
-    def tearDown(self):
-        """ Destroy any unit test resources. """
-        pass
-
     def test_count(self):
         """ Check that there are 3 FM/AM/SSB/SSTV QSOs and 1 CW QSO. Note that the BAND must be specified in order to be counted. """
         count = self.awards.count(self.logbook)
diff --git a/tests/test_cabrillo.py b/tests/test_cabrillo.py
index 0934608..c632709 100644
--- a/tests/test_cabrillo.py
+++ b/tests/test_cabrillo.py
@@ -26,12 +26,10 @@ class TestCabrillo(unittest.TestCase):
     """ The unit tests for the Cabrillo class. """
 
     def setUp(self):
+        """ Set up the Cabrillo object needed for the unit tests. """
         self.cabrillo = Cabrillo()
         return
 
-    def tearDown(self):
-        return
-
     def test_write(self):
         """ Check that QSOs are written correctly in Cabrillo format. """
         records = [{'TIME_ON': '1955', 'BAND': '40m', 'CALL': 'TEST', 'FREQ': "145.550", 'MODE': 'FM', 'QSO_DATE': '20130322', 'RST_SENT': '59 001', 'RST_RCVD': '59 002'}, {'TIME_ON': '0820', 'BAND': '20m', 'CALL': 'TEST2ABC', 'FREQ': "144.330", 'MODE': 'SSB', 'QSO_DATE': '20150227', 'RST_SENT': '55 020', 'RST_RCVD': '57 003'}, {'TIME_ON': '0832', 'BAND': '2m', 'CALL': 'HELLO', 'FREQ': "145.550", 'MODE': 'FM', 'QSO_DATE': '20150227', 'RST_SENT': '59 001', 'RST_RCVD': '59 002'}]
diff --git a/tests/test_calendar_dialog.py b/tests/test_calendar_dialog.py
index 81b2417..dc59523 100644
--- a/tests/test_calendar_dialog.py
+++ b/tests/test_calendar_dialog.py
@@ -37,10 +37,6 @@ class TestCalendarDialog(unittest.TestCase):
         self.cd.calendar.select_month(3, 2017)  # Note: Months start from 0 when using the Calendar widget. So "3" represents April here.
         self.cd.calendar.select_day(2)
 
-    def tearDown(self):
-        """ Destroy any unit test resources. """
-        pass
-
     def test_date(self):
         """ Check that the date obtained from the Calendar is in the correct format. """
         assert(self.cd.date == "20170402")
diff --git a/tests/test_callsign_lookup.py b/tests/test_callsign_lookup.py
index 090f477..5470980 100644
--- a/tests/test_callsign_lookup.py
+++ b/tests/test_callsign_lookup.py
@@ -27,17 +27,13 @@ from pyqso.callsign_lookup import *
 
 class TestCallsignLookup(unittest.TestCase):
 
-    """ The unit tests for the CallsignLookup class. """
+    """ The unit tests for the callsign lookup functionality. """
 
     def setUp(self):
         """ Set up the objects needed for the unit tests. """
         self.qrz = CallsignLookupQRZ(parent=None)
         self.hamqth = CallsignLookupHamQTH(parent=None)
 
-    def tearDown(self):
-        """ Destroy any unit test resources. """
-        pass
-
     def test_strip(self):
         """ Check that a callsign with a prefix and a suffix is stripped correctly. """
         callsign = "EA3/MYCALL/MM"
diff --git a/tests/test_compare.py b/tests/test_compare.py
index bd355f2..b1aeda6 100644
--- a/tests/test_compare.py
+++ b/tests/test_compare.py
@@ -24,9 +24,11 @@ from pyqso.compare import *
 
 class TestCompare(unittest.TestCase):
 
-    """ The unit tests for the Compare class. """
+    """ The unit tests for the comparison schemes. """
 
     def setUp(self):
+        """ Set up the objects needed for the unit tests. """
+
         data_types = [int] + [str]*3
         self.model = Gtk.ListStore(*data_types)
         row1 = [0, "100", "20150323", "1433"]
@@ -39,9 +41,6 @@ class TestCompare(unittest.TestCase):
         self.model.append(row4)
         return
 
-    def tearDown(self):
-        return
-
     def test_compare_default(self):
         """ Check the correctness of the default comparison scheme. """
 
diff --git a/tests/test_dx_cluster.py b/tests/test_dx_cluster.py
index 05a334e..12a8f04 100644
--- a/tests/test_dx_cluster.py
+++ b/tests/test_dx_cluster.py
@@ -31,13 +31,10 @@ class TestDXCluster(unittest.TestCase):
 
     def setUp(self):
         """ Set up the objects needed for the unit tests. """
+
         PyQSO = mock.MagicMock()
         self.dxcluster = DXCluster(application=PyQSO())
 
-    def tearDown(self):
-        """ Destroy any unit test resources. """
-        pass
-
     def test_on_telnet_io(self):
         """ Check that the response from the Telnet server can be correctly decoded. """
 
diff --git a/tests/test_log.py b/tests/test_log.py
index faed907..d63adfa 100644
--- a/tests/test_log.py
+++ b/tests/test_log.py
@@ -26,6 +26,7 @@ class TestLog(unittest.TestCase):
     """ The unit tests for the Log class. """
 
     def setUp(self):
+        """ Create a connection to a temporary database and set up the objects needed for the unit tests. """
         self.connection = sqlite.connect(":memory:")
         self.connection.row_factory = sqlite.Row
 
@@ -43,21 +44,26 @@ class TestLog(unittest.TestCase):
         self.log = Log(self.connection, "test")
 
     def tearDown(self):
+        """ Destroy the connection to the temporary database. """
         self.connection.close()
 
     def test_add_missing_db_columns(self):
-
-        column_names_before = []
-        column_names_after = []
+        """ Check that any missing columns in the database are added successfully. """
 
         c = self.connection.cursor()
+
+        # 'Before' state.
+        column_names_before = []
         c.execute("PRAGMA table_info(test)")
         result = c.fetchall()
         for t in result:
             column_names_before.append(t[1].upper())
 
+        # Add missing columns.
         self.log.add_missing_db_columns()
 
+        # 'After' state.
+        column_names_after = []
         c.execute("PRAGMA table_info(test)")
         result = c.fetchall()
         for t in result:
@@ -66,24 +72,43 @@ class TestLog(unittest.TestCase):
         print("Column names before: ", column_names_before)
         print("Column names after: ", column_names_after)
 
-        assert(len(column_names_before) == len(self.field_names) + 1)  # Added 1 here because of the "ID" column in all database tables.
+        assert(len(column_names_before) == len(self.field_names) + 1)  # Added 1 here because of the "id" column in all database tables.
         assert(len(column_names_after) == len(AVAILABLE_FIELD_NAMES_ORDERED) + 1)
         for field_name in AVAILABLE_FIELD_NAMES_ORDERED:
             assert(field_name in column_names_after)
 
     def test_add_record(self):
+        """ Check that a single record can be successfully added. """
+
         self.log.add_record(self.fields_and_data)
+
         c = self.connection.cursor()
         c.execute("SELECT * FROM test")
         records = c.fetchall()
-
         assert len(records) == 1
 
+        # Check that all the data has been added to all the fields.
         for field_name in self.field_names:
             print(self.fields_and_data[field_name], records[0][field_name])
             assert self.fields_and_data[field_name] == records[0][field_name]
 
+        # Check consistency of index between Gtk.ListStore and the database.
+        assert(records[0]["id"] == 1)
+        iter = self.log.get_iter_first()
+        row_index = self.log.get_value(iter, 0)
+        assert(records[0]["id"] == row_index)
+
+    def test_add_record_multiple(self):
+        """ Check that multiple records can be successfully added in one go. """
+        self.log.add_record([self.fields_and_data]*5)
+
+        c = self.connection.cursor()
+        c.execute("SELECT * FROM test")
+        records = c.fetchall()
+        assert len(records) == 5
+
     def test_delete_record(self):
+        """ Check that a record can be successfully deleted. """
         query = "INSERT INTO test VALUES (NULL, ?, ?, ?, ?, ?, ?, ?, ?)"
         c = self.connection.cursor()
         c.execute(query, (self.fields_and_data["CALL"], self.fields_and_data["QSO_DATE"], self.fields_and_data["TIME_ON"], self.fields_and_data["FREQ"], self.fields_and_data["BAND"], self.fields_and_data["MODE"], self.fields_and_data["RST_SENT"], self.fields_and_data["RST_RCVD"]))
@@ -100,6 +125,7 @@ class TestLog(unittest.TestCase):
         assert(len(records_after) == 0)
 
     def test_edit_record(self):
+        """ Check that a record's fields can be successfully edited. """
         query = "INSERT INTO test VALUES (NULL, ?, ?, ?, ?, ?, ?, ?, ?)"
         c = self.connection.cursor()
         c.execute(query, (self.fields_and_data["CALL"], self.fields_and_data["QSO_DATE"], self.fields_and_data["TIME_ON"], self.fields_and_data["FREQ"], self.fields_and_data["BAND"], self.fields_and_data["MODE"], self.fields_and_data["RST_SENT"], self.fields_and_data["RST_RCVD"]))
@@ -119,6 +145,7 @@ class TestLog(unittest.TestCase):
         assert(record_after["FREQ"] == "145.450")
 
     def test_get_record_by_index(self):
+        """ Check that a record can be retrieved using its index. """
         query = "INSERT INTO test VALUES (NULL, ?, ?, ?, ?, ?, ?, ?, ?)"
         c = self.connection.cursor()
         c.execute(query, (self.fields_and_data["CALL"], self.fields_and_data["QSO_DATE"], self.fields_and_data["TIME_ON"], self.fields_and_data["FREQ"], self.fields_and_data["BAND"], self.fields_and_data["MODE"], self.fields_and_data["RST_SENT"], self.fields_and_data["RST_RCVD"]))
@@ -133,6 +160,7 @@ class TestLog(unittest.TestCase):
         assert(len(record) == len(self.fields_and_data) + 1)
 
     def test_records(self):
+        """ Check that all records in a log can be successfully retrieved. """
         query = "INSERT INTO test VALUES (NULL, ?, ?, ?, ?, ?, ?, ?, ?)"
         c = self.connection.cursor()
         # Add the same record twice
@@ -147,6 +175,7 @@ class TestLog(unittest.TestCase):
             assert(records[1][field_name] == self.fields_and_data[field_name])
 
     def test_record_count(self):
+        """ Check that the total number of records in a log is calculated correctly. """
         query = "INSERT INTO test VALUES (NULL, ?, ?, ?, ?, ?, ?, ?, ?)"
         c = self.connection.cursor()
         # Add the same record twice
@@ -158,6 +187,7 @@ class TestLog(unittest.TestCase):
         assert(record_count == 2)  # There should be 2 records
 
     def test_get_duplicates(self):
+        """ Insert n records, n-1 of which are duplicates, and check that the duplicates are successfully identified. """
         query = "INSERT INTO test VALUES (NULL, ?, ?, ?, ?, ?, ?, ?, ?)"
         c = self.connection.cursor()
         n = 5  # The total number of records to insert.
@@ -165,7 +195,20 @@ class TestLog(unittest.TestCase):
             c.execute(query, (self.fields_and_data["CALL"], self.fields_and_data["QSO_DATE"], self.fields_and_data["TIME_ON"], self.fields_and_data["FREQ"], self.fields_and_data["BAND"], self.fields_and_data["MODE"], self.fields_and_data["RST_SENT"], self.fields_and_data["RST_RCVD"]))
         assert(len(self.log.get_duplicates()) == n-1)  # Expecting n-1 duplicates.
 
+    def test_remove_duplicates(self):
+        """ Insert n records, n-1 of which are duplicates, and check that the duplicates are successfully removed. """
+        n = 5  # The total number of records to insert.
+        for i in range(0, n):
+            self.log.add_record(self.fields_and_data)
+        (number_of_duplicates, number_of_duplicates_removed) = self.log.remove_duplicates()
+        print("Number of duplicates: %d" % number_of_duplicates)
+        print("Number of duplicates removed: %d" % number_of_duplicates_removed)
+        assert(number_of_duplicates == number_of_duplicates_removed)
+        assert(number_of_duplicates == 4)
+        assert(self.log.record_count == 1)
+
     def test_rename(self):
+        """ Check that a log can be successfully renamed. """
         old_name = "test"
         new_name = "hello"
         success = self.log.rename(new_name)
diff --git a/tests/test_printer.py b/tests/test_printer.py
index b767d4c..82358d5 100644
--- a/tests/test_printer.py
+++ b/tests/test_printer.py
@@ -37,10 +37,6 @@ class TestPrinter(unittest.TestCase):
         self.printer = Printer(application=PyQSO())
         self.printer.application.window = Gtk.Window()
 
-    def tearDown(self):
-        """ Destroy any unit test resources. """
-        return
-
     def test_print_records(self):
         """ Check that a list of records can be printed to a PDF file. """
         self.printer.action = Gtk.PrintOperationAction.EXPORT
diff --git a/tests/test_record_dialog.py b/tests/test_record_dialog.py
index 500ed37..b6ec67b 100644
--- a/tests/test_record_dialog.py
+++ b/tests/test_record_dialog.py
@@ -31,6 +31,7 @@ class TestRecordDialog(unittest.TestCase):
     """ The unit tests for the RecordDialog class. """
 
     def setUp(self):
+        """ Set up the objects needed for the unit tests. """
         PyQSO = mock.MagicMock()
         self.record_dialog = RecordDialog(application=PyQSO(), log=None)
 
@@ -51,9 +52,6 @@ class TestRecordDialog(unittest.TestCase):
 
         return
 
-    def tearDown(self):
-        return
-
     def test_autocomplete_band(self):
         """ Given a frequency, check that the band field is automatically set to the correct value. """
         self.record_dialog.sources["FREQ"].set_text("145.525")
diff --git a/tests/test_summary.py b/tests/test_summary.py
index f105ea6..018d267 100644
--- a/tests/test_summary.py
+++ b/tests/test_summary.py
@@ -32,7 +32,7 @@ class TestSummary(unittest.TestCase):
     """ The unit tests for the Summary class. """
 
     def setUp(self):
-        """ Set up the objects needed for the unit tests. """
+        """ Set up the objects needed for the unit tests and create a connection to the test database. """
         PyQSO = mock.MagicMock()
         self.summary = Summary(application=PyQSO())
         self.summary.logbook = Logbook(application=PyQSO())
@@ -43,7 +43,7 @@ class TestSummary(unittest.TestCase):
         assert(self.summary.logbook.logs is not None)
 
     def tearDown(self):
-        """ Destroy any unit test resources. """
+        """ Destroy the connection to the test database. """
         success = self.summary.logbook.db_disconnect()
         assert(success)