diff --git a/code/utils/outlier.py b/code/utils/functions/outlier.py
similarity index 100%
rename from code/utils/outlier.py
rename to code/utils/functions/outlier.py
diff --git a/code/utils/tests/test_outliers.py b/code/utils/tests/test_outliers.py
new file mode 100644
index 0000000..0ae1ba9
--- /dev/null
+++ b/code/utils/tests/test_outliers.py
@@ -0,0 +1,58 @@
+""" Tests functions in outliers module
+Largely lifted straight from the tests provided for diagnostics.py in HW2 and janewliang's diagnosis_script.py
+
+Run at the project directory with:
+    nosetests code/utils/tests/test_outliers.py
+"""
+
+# Loading modules.
+import os
+import sys
+import numpy as np
+import nibabel as nib
+from nose.tools import assert_equal
+from numpy.testing import assert_almost_equal, assert_array_equal
+
+
+# Add path to functions to the system path.
+sys.path.append(os.path.join(os.path.dirname(__file__), "../functions/"))
+
+from outlier import *
+project_path=os.path.join(os.path.dirname(__file__), '../../../')
+
+def test_vol_std():
+    # create the test data
+    shape = (2, 3, 4)
+    L = np.prod(shape)
+    t = 10
+    data_2d = np.random.normal(size=(L, t))
+    test_stds = np.std(data_2d, axis=0)
+    data_4d = np.reshape(data_2d, shape + (t,))
+    stds = vol_std(data_4d)
+    assert_almost_equal(test_stds, stds)
+
+def test_iqr_outliers():
+    data = np.arange(101)
+    # the data is from 0 to 100, so the iqr = 50
+    exp_lo = 25 - 1.5*50
+    exp_hi = 75 + 1.5*50
+    indices, thresholds = iqr_outliers(data)
+    assert_array_equal(indices, [])
+    assert_equal(thresholds, (exp_lo, exp_hi))
+    # Reverse the data
+    # check the results will not change
+    indices, thresholds = iqr_outliers(data[::-1])
+    assert_array_equal(indices, [])
+    assert_equal(thresholds, (exp_lo, exp_hi))
+    # Add outliers
+    data[0] = -100
+    data[1] = 200
+    data[100] = 1
+    indices, thresholds = iqr_outliers(data)
+    assert_array_equal(indices, [0, 1])
+    assert_equal(thresholds, (exp_lo, exp_hi))
+    # Reversed the data
+    indices, thresholds = iqr_outliers(data[::-1])
+    assert_array_equal(indices, [99, 100])
+    assert_equal(thresholds, (exp_lo, exp_hi))
+