diff --git a/dimod/response.py b/dimod/response.py
index d3b2c38d..59d96329 100644
--- a/dimod/response.py
+++ b/dimod/response.py
@@ -87,21 +87,24 @@ class Response(Iterable, Sized):
         self._samples_matrix = samples_matrix
         num_samples, num_variables = samples_matrix.shape
 
-        if not isinstance(data_vectors, dict):
+        if not isinstance(data_vectors, Mapping):
             raise TypeError("expected 'data_vectors' to be a dict")
         if 'energy' not in data_vectors:
             raise ValueError("energy must be provided")
         else:
-            data_vectors = data_vectors.copy()  # shallow copy
-            data_vectors['energy'] = np.asarray(data_vectors['energy'])
-        for vector in data_vectors.values():
-            # todo - check that is a vector and that has the right length
-            if isinstance(vector, (np.ndarray, list)):
-                if len(vector) != num_samples:
-                    raise ValueError(("expected data vector {} (length {}) to be a vector of length {}"
-                                      "").format(vector, len(vector), num_samples))
-            else:
-                raise TypeError("expected data vector {} to be a list of NumPy array".format(vector))
+            data_vectors = dict(data_vectors)  # shallow copy
+
+        for key, vector in iteritems(data_vectors):
+            try:
+                data_vectors[key] = vector = np.asarray(vector)
+            except (ValueError, TypeError):
+                raise TypeError("expected data vector {} to be array-like".format(key))
+
+            shape = vector.shape
+            if not shape or shape[0] != num_samples:
+                raise ValueError(("expected data vector {} (shape {}) to have {} rows"
+                                  "").format(key, vector.shape, num_samples))
+
         self._data_vectors = data_vectors
 
         # vartype is checked by the decorator
@@ -824,10 +827,13 @@ class Response(Iterable, Sized):
     # Viewing a Response
     ###############################################################################################
 
-    def samples(self, sorted_by='energy'):
+    def samples(self, n=None, sorted_by='energy'):
         """Iterate over the samples in the response.
 
         Args:
+            n (int, optional, default=None):
+                The maximum number of samples to provide. If None, all are provided.
+
             sorted_by (str/None, optional, default='energy'):
                 Selects the `data_vector` used to sort the samples. If None, the samples are yielded in
                 the order given by the samples matrix.
@@ -861,13 +867,21 @@ class Response(Iterable, Sized):
             {'a': -1, 'b': 1}
 
         """
+        num_samples = len(self)
+
+        if n is not None:
+            for sample in itertools.islice(self.samples(n=None, sorted_by=sorted_by), n):
+                yield sample
+            return
+
         if sorted_by is None:
-            order = np.arange(len(self))
+            order = np.arange(num_samples)
         else:
             order = np.argsort(self.data_vectors[sorted_by])
 
         samples = self.samples_matrix
         label_mapping = self.label_to_idx
+
         for idx in order:
             yield SampleView(idx, self)
 

data_vectors should have either numpy array values, or a list values, but not both.
https://github.com/dwavesystems/dimod/blob/7b75e47ce4fec541e432f84367ba58393934b941/dimod/response.py#L40

Making it be more than one thing requires the parser of the response to inspect the object before using it. If we want to have the benefits of a numpy array for some of the data_vectors, I think it's worth it to make everything a numpy array

If we don't need it to be a numpy array, might as well make them all lists?
diff --git a/tests/test_response.py b/tests/test_response.py
index 73c1091e..6c5f827e 100644
--- a/tests/test_response.py
+++ b/tests/test_response.py
@@ -54,7 +54,7 @@ class TestResponse(unittest.TestCase):
         npt.assert_equal(samples_matrix, response.samples_matrix)
         npt.assert_allclose(energies, response.data_vectors['energy'])
 
-    def test_data_vector_copy(self):
+    def test_data_vectors_copy(self):
         samples_matrix = np.matrix([[0, 1, 0, 1],
                                     [1, 0, 1, 0],
                                     [0, 0, 0, 0],
@@ -66,6 +66,80 @@ class TestResponse(unittest.TestCase):
 
         self.assertIsNot(response.data_vectors, data_vectors)
 
+    def test_data_vectors_are_arrays(self):
+        samples_matrix = np.matrix([[0, 1, 0, 1],
+                                    [1, 0, 1, 0],
+                                    [0, 0, 0, 0],
+                                    [1, 1, 1, 1]])
+        energies = [2, 2, 0, 4]
+        num_occurrences = [1, 1, 2, 1]
+        objects = [object() for __ in range(4)]
+
+        data_vectors = {'energy': energies, 'occurences': num_occurrences, 'objects': objects}
+
+        response = dimod.Response(samples_matrix, data_vectors, dimod.BINARY)
+
+        self.assertEqual(len(response.data_vectors), 3)
+
+        for key in data_vectors:
+            self.assertIn(key, response.data_vectors)
+
+            vector = response.data_vectors[key]
+
+            self.assertIsInstance(vector, np.ndarray)
+
+            self.assertEqual(vector.shape, (4,))
+
+    def test_data_vectors_wrong_length(self):
+        samples_matrix = np.matrix([[0, 1, 0, 1],
+                                    [1, 0, 1, 0],
+                                    [0, 0, 0, 0],
+                                    [1, 1, 1, 1]])
+        energies = [2, 2, 0, 4]
+        num_occurrences = [1, 1, 2, 1, 1]
+        objects = [object() for __ in range(4)]
+
+        data_vectors = {'energy': energies, 'occurences': num_occurrences, 'objects': objects}
+
+        with self.assertRaises(ValueError):
+            response = dimod.Response(samples_matrix, data_vectors, dimod.BINARY)
+
+    def test_data_vectors_not_array_like(self):
+        samples_matrix = np.matrix([[0, 1, 0, 1],
+                                    [1, 0, 1, 0],
+                                    [0, 0, 0, 0],
+                                    [1, 1, 1, 1]])
+        energies = [2, 2, 0, 4]
+        num_occurrences = 'hi there'
+        objects = [object() for __ in range(4)]
+
+        data_vectors = {'energy': energies, 'occurences': num_occurrences, 'objects': objects}
+
+        with self.assertRaises(ValueError):
+            response = dimod.Response(samples_matrix, data_vectors, dimod.BINARY)
+
+    def test_samples_num_limited(self):
+        samples_matrix = np.matrix([[0, 1, 0, 1],
+                                    [1, 0, 1, 0],
+                                    [0, 0, 0, 0],
+                                    [1, 1, 1, 1]])
+        energies = [2, 2, 0, 4]
+        num_occurrences = [1, 1, 2, 1]
+        objects = [object() for __ in range(4)]
+
+        data_vectors = {'energy': energies, 'occurences': num_occurrences, 'objects': objects}
+
+        response = dimod.Response(samples_matrix, data_vectors, dimod.BINARY)
+
+        samples_list = list(response.samples())
+
+        self.assertEqual(len(samples_list), 4)
+
+        shortened_samples_list = list(response.samples(3))
+
+        self.assertEqual(len(shortened_samples_list), 3)
+        self.assertEqual(shortened_samples_list, samples_list[0:3])
+
     def test_instantiation_without_energy(self):
         samples_matrix = np.matrix([[0, 1, 0, 1],
                                     [1, 0, 1, 0],

pip install -e .[all]
parse_log_pytest
requirements.txt
pytest pytest-cov pytest-xdist pytest-mock pytest-asyncio
apt-get update apt-get install -y gcc
3.6
requirements.txt tests/requirements.txt docs/requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
alabaster==0.7.13
attrs==22.2.0
Babel==2.11.0
certifi==2021.5.30
charset-normalizer==2.0.12
coverage==6.2
coveralls==3.3.1
decorator==5.1.1
-e git+https://github.com/dwavesystems/dimod.git@7b75e47ce4fec541e432f84367ba58393934b941#egg=dimod
docopt==0.6.2
docutils==0.18.1
enum34==1.1.6
execnet==1.9.0
idna==3.10
imagesize==1.4.1
importlib-metadata==4.8.3
iniconfig==1.1.1
Jinja2==3.0.3
jsonschema==2.6.0
MarkupSafe==2.0.1
mock==2.0.0
networkx==2.0
numpy==1.11.3
packaging==21.3
pandas==0.22.0
pbr==6.1.1
pluggy==1.0.0
py==1.11.0
Pygments==2.14.0
pyparsing==3.1.4
pytest==7.0.1
pytest-asyncio==0.16.0
pytest-cov==4.0.0
pytest-mock==3.6.1
pytest-xdist==3.0.2
python-dateutil==2.9.0.post0
pytz==2025.2
requests==2.27.1
six==1.11.0
snowballstemmer==2.2.0
Sphinx==5.3.0
sphinx-rtd-theme==2.0.0
sphinxcontrib-applehelp==1.0.2
sphinxcontrib-devhelp==1.0.2
sphinxcontrib-htmlhelp==2.0.0
sphinxcontrib-jquery==4.1
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-qthelp==1.0.3
sphinxcontrib-serializinghtml==1.1.5
tomli==1.2.3
typing_extensions==4.1.1
urllib3==1.26.20
zipp==3.6.0

name: dimod
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - alabaster==0.7.13
      - attrs==22.2.0
      - babel==2.11.0
      - charset-normalizer==2.0.12
      - coverage==6.2
      - coveralls==3.3.1
      - decorator==5.1.1
      - docopt==0.6.2
      - docutils==0.18.1
      - enum34==1.1.6
      - execnet==1.9.0
      - idna==3.10
      - imagesize==1.4.1
      - importlib-metadata==4.8.3
      - iniconfig==1.1.1
      - jinja2==3.0.3
      - jsonschema==2.6.0
      - markupsafe==2.0.1
      - mock==2.0.0
      - networkx==2.0
      - numpy==1.11.3
      - packaging==21.3
      - pandas==0.22.0
      - pbr==6.1.1
      - pluggy==1.0.0
      - py==1.11.0
      - pygments==2.14.0
      - pyparsing==3.1.4
      - pytest==7.0.1
      - pytest-asyncio==0.16.0
      - pytest-cov==4.0.0
      - pytest-mock==3.6.1
      - pytest-xdist==3.0.2
      - python-dateutil==2.9.0.post0
      - pytz==2025.2
      - requests==2.27.1
      - six==1.11.0
      - snowballstemmer==2.2.0
      - sphinx==5.3.0
      - sphinx-rtd-theme==2.0.0
      - sphinxcontrib-applehelp==1.0.2
      - sphinxcontrib-devhelp==1.0.2
      - sphinxcontrib-htmlhelp==2.0.0
      - sphinxcontrib-jquery==4.1
      - sphinxcontrib-jsmath==1.0.1
      - sphinxcontrib-qthelp==1.0.3
      - sphinxcontrib-serializinghtml==1.1.5
      - tomli==1.2.3
      - typing-extensions==4.1.1
      - urllib3==1.26.20
      - zipp==3.6.0
prefix: /opt/conda/envs/dimod

tests/test_response.py::TestResponse::test_data_vectors_are_arrays tests/test_response.py::TestResponse::test_data_vectors_not_array_like tests/test_response.py::TestResponse::test_samples_num_limited
tests/test_response.py::TestResponse::test__iter__ tests/test_response.py::TestResponse::test_change_vartype_copy tests/test_response.py::TestResponse::test_change_vartype_inplace tests/test_response.py::TestResponse::test_data_docstrings tests/test_response.py::TestResponse::test_data_vectors_copy tests/test_response.py::TestResponse::test_data_vectors_wrong_length tests/test_response.py::TestResponse::test_empty tests/test_response.py::TestResponse::test_from_dicts tests/test_response.py::TestResponse::test_from_dicts_unlike_labels tests/test_response.py::TestResponse::test_from_dicts_unsortable_labels tests/test_response.py::TestResponse::test_from_futures tests/test_response.py::TestResponse::test_from_futures_column_subset tests/test_response.py::TestResponse::test_from_futures_extra_keys tests/test_response.py::TestResponse::test_from_futures_typical tests/test_response.py::TestResponse::test_from_matrix tests/test_response.py::TestResponse::test_from_pandas tests/test_response.py::TestResponse::test_infer_vartype tests/test_response.py::TestResponse::test_instantiation tests/test_response.py::TestResponse::test_instantiation_without_energy tests/test_response.py::TestResponse::test_partial_relabel tests/test_response.py::TestResponse::test_partial_relabel_inplace tests/test_response.py::TestResponse::test_relabel_copy tests/test_response.py::TestResponse::test_relabel_docstring tests/test_response.py::TestResponse::test_update tests/test_response.py::TestResponse::test_update_energy
dimod/response.py
dimod/response.py