diff --git a/sorting-searching/insertion-sort.ipynb b/sorting-searching/insertion-sort.ipynb
index d93a6fc..4146ed2 100644
--- a/sorting-searching/insertion-sort.ipynb
+++ b/sorting-searching/insertion-sort.ipynb
@@ -13,20 +13,23 @@
    "source": [
     "## Problem: Implement insertion sort.\n",
     "\n",
-    "* [Clarifying Questions](#Clarifying-Questions)\n",
+    "* [Constraints and Assumptions](#Constraints-and-Assumptions)\n",
     "* [Test Cases](#Test-Cases)\n",
     "* [Algorithm](#Algorithm)\n",
     "* [Code](#Code)\n",
-    "* [Pythonic-Code](#Pythonic-Code)"
+    "* [Unit Test](#Unit-Test)"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Clarifying Questions\n",
+    "## Constraints and Assumptions\n",
     "\n",
-    "* None"
+    "*Problem statements are often intentionally ambiguous.  Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
+    "\n",
+    "* Are you looking for a naiive solution?\n",
+    "    * Yes"
    ]
   },
   {
@@ -70,7 +73,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
    "metadata": {
     "collapsed": false
    },
@@ -89,25 +92,57 @@
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
+   "cell_type": "markdown",
+   "metadata": {},
    "source": [
-    "print('Empty input')\n",
-    "data = []\n",
-    "insertion_sort(data)\n",
-    "print(data)\n",
-    "print('One element')\n",
-    "data = [5]\n",
-    "insertion_sort(data)\n",
-    "print(data)\n",
-    "print('Two or more elements')\n",
-    "data = [5, 1, 7, 2, 6, -3, 5, 7, -1]\n",
-    "insertion_sort(data)\n",
-    "print(data)"
+    "## Unit Test\n",
+    "\n",
+    "*It is important to identify and run through general and edge cases from the [Test Cases](#Test-Cases) section by hand.  You generally will not be asked to write a unit test like what is shown below.*"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Empty input\n",
+      "One element\n",
+      "Two or more elements\n",
+      "Success: test_insertion_sort\n"
+     ]
+    }
+   ],
+   "source": [
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "class Test(object):\n",
+    "    def test_insertion_sort(self):\n",
+    "        print('Empty input')\n",
+    "        data = []\n",
+    "        insertion_sort(data)\n",
+    "        assert_equal(data, [])\n",
+    "\n",
+    "        print('One element')\n",
+    "        data = [5]\n",
+    "        insertion_sort(data)\n",
+    "        assert_equal(data, [5])\n",
+    "\n",
+    "        print('Two or more elements')\n",
+    "        data = [5, 1, 7, 2, 6, -3, 5, 7, -1]\n",
+    "        insertion_sort(data)\n",
+    "        assert_equal(data, sorted(data))\n",
+    "        \n",
+    "        print('Success: test_insertion_sort')\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    test = Test()\n",
+    "    test.test_insertion_sort()"
    ]
   }
  ],