diff --git a/arrays-strings/unique_chars.ipynb b/arrays-strings/unique_chars.ipynb
index 21d5a62..350476d 100644
--- a/arrays-strings/unique_chars.ipynb
+++ b/arrays-strings/unique_chars.ipynb
@@ -20,7 +20,8 @@
     "* [Algorithm 2: Hash Map Lookup](#Algorithm-2:-Hash-Map-Lookup)\n",
     "* [Code: Hash Map Lookup](#Code:-Hash-Map-Lookup)\n",
     "* [Algorithm 3: In-Place](#Algorithm-3:-In-Place)\n",
-    "* [Code: In-Place](#Code:-In-Place)"
+    "* [Code: In-Place](#Code:-In-Place)\n",
+    "* [Unit Test](#Unit-Test)"
    ]
   },
   {
@@ -28,8 +29,12 @@
    "metadata": {},
    "source": [
     "## Clarifying Questions\n",
-    "* Is the string in ASCII (extended?) or Unicode?  \n",
-    "    * ASCII extended, which is 256 characters\n",
+    "\n",
+    "*Problem statements are sometimes intentionally ambiguous.  Asking clarifying questions, identifying constraints, and stating assumptions help to ensure you code the intended solution.*\n",
+    "\n",
+    "* Can I assume the string is ASCII?\n",
+    "    * Yes\n",
+    "    * Note: Unicode strings could require special handling depending on your language\n",
     "* Can you use additional data structures?  \n",
     "    * Yes"
    ]
@@ -40,32 +45,13 @@
    "source": [
     "## Test Cases\n",
     "\n",
+    "*Identifying and running through general and edge cases are important.  You generally will not be asked to write a unit test like what is shown below.*\n",
+    "\n",
     "* '' -> True\n",
     "* 'foo' -> False\n",
     "* 'bar' -> True"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [],
-   "source": [
-    "from nose.tools import assert_equal\n",
-    "\n",
-    "class Test(object):\n",
-    "  def test_unique_chars(self, func):\n",
-    "        assert_equal(func(''), True)\n",
-    "        assert_equal(func('foo'), False)\n",
-    "        assert_equal(func('bar'), True)\n",
-    "\n",
-    "def run_tests(func):\n",
-    "    test = Test()\n",
-    "    test.test_unique_chars(func)"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -93,16 +79,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
    "metadata": {
     "collapsed": false
    },
    "outputs": [],
    "source": [
     "def unique_chars(string):\n",
-    "    return len(set(string)) == len(string)\n",
-    "\n",
-    "run_tests(unique_chars)"
+    "    return len(set(string)) == len(string)"
    ]
   },
   {
@@ -138,7 +122,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {
     "collapsed": false
    },
@@ -151,9 +135,7 @@
     "            return False\n",
     "        else:\n",
     "            chars_set.add(char)\n",
-    "    return True\n",
-    "\n",
-    "run_tests(unique_chars_hash)"
+    "    return True"
    ]
   },
   {
@@ -184,7 +166,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {
     "collapsed": false
    },
@@ -194,9 +176,48 @@
     "    for char in string:\n",
     "        if string.count(char) > 1:\n",
     "            return False\n",
-    "    return True\n",
+    "    return True"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Success: test_unique_chars\n",
+      "Success: test_unique_chars\n",
+      "Success: test_unique_chars\n"
+     ]
+    }
+   ],
+   "source": [
+    "from nose.tools import assert_equal\n",
     "\n",
-    "run_tests(unique_chars_inplace)"
+    "class Test(object):\n",
+    "  def test_unique_chars(self, func):\n",
+    "        assert_equal(func(''), True)\n",
+    "        assert_equal(func('foo'), False)\n",
+    "        assert_equal(func('bar'), True)\n",
+    "        print('Success: test_unique_chars')\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    test = Test()\n",
+    "    test.test_unique_chars(unique_chars)\n",
+    "    test.test_unique_chars(unique_chars_hash)\n",
+    "    test.test_unique_chars(unique_chars_inplace)"
    ]
   }
  ],