diff --git a/src/lighteval/metrics/imports/data_stats_utils.py b/src/lighteval/metrics/imports/data_stats_utils.py
index c5ae00725..a6c528910 100644
--- a/src/lighteval/metrics/imports/data_stats_utils.py
+++ b/src/lighteval/metrics/imports/data_stats_utils.py
@@ -68,7 +68,11 @@ def strings(self, min_length=0, summary_base=True):
 
         # Generate strings, filtering out strings below the minimum length.
 
-        strings = [base[i : i + length] for i, j, length in self.overlaps() if length > min_length]
+        strings = []
+        for i, j, length in self.overlaps():
+            if length > min_length:
+                start = i if summary_base else j
+                strings.append(base[start : start + length])
 
         # By default, we just return the tokenization being used.
         # But if they user wants a raw string, then we convert.
diff --git a/tests/unit/metrics/test_data_stats_utils.py b/tests/unit/metrics/test_data_stats_utils.py
new file mode 100644
index 000000000..faaaf9aaa
--- /dev/null
+++ b/tests/unit/metrics/test_data_stats_utils.py
@@ -0,0 +1,57 @@
+# MIT License
+
+# Copyright (c) 2024 The HuggingFace Team
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+import unittest
+
+from lighteval.metrics.imports.data_stats_utils import Fragments
+
+
+class TestFragmentsStrings(unittest.TestCase):
+    def test_source_offset_and_original_case(self):
+        fragments = Fragments("cat sat", "The Cat sat on the mat")
+        self.assertEqual(fragments.overlaps(), [Fragments.Match(0, 1, 2)])
+        self.assertEqual(fragments.strings(summary_base=False), [["Cat", "sat"]])
+
+    def test_summary_offset_is_unchanged(self):
+        fragments = Fragments("cat sat", "The Cat sat on the mat")
+        self.assertEqual(fragments.strings(), [["cat", "sat"]])
+
+    def test_multiple_source_spans(self):
+        fragments = Fragments(["cat", "sat", "new", "dog"], ["prefix", "Dog", "then", "Cat", "sat"])
+        self.assertEqual(fragments.strings(summary_base=False), [["Cat", "sat"], ["Dog"]])
+        self.assertEqual(fragments.strings(), [["cat", "sat"], ["dog"]])
+
+    def test_threshold_retains_existing_strict_semantics(self):
+        fragments = Fragments("cat sat new dog", "prefix Dog then Cat sat")
+        self.assertEqual(fragments.strings(min_length=1, summary_base=False), [["Cat", "sat"]])
+        self.assertEqual(fragments.strings(min_length=2, summary_base=False), [])
+
+    def test_no_overlap(self):
+        self.assertEqual(Fragments("cat", "dog").strings(summary_base=False), [])
+        self.assertEqual(Fragments("", "dog").strings(summary_base=False), [])
+
+    def test_metrics_and_matches_do_not_mutate(self):
+        fragments = Fragments("cat sat", "The Cat sat on the mat")
+        before = (fragments.overlaps()[:], fragments.coverage(), fragments.density(), fragments.compression())
+        fragments.strings(summary_base=False)
+        after = (fragments.overlaps(), fragments.coverage(), fragments.density(), fragments.compression())
+        self.assertEqual(before, after)