diff --git a/Petz_2024_HNA-tutorial.ipynb b/Petz_2024_HNA-tutorial.ipynb
index 0f1acea..64cdb04 100644
--- a/Petz_2024_HNA-tutorial.ipynb
+++ b/Petz_2024_HNA-tutorial.ipynb
@@ -164,9 +164,10 @@
     "# Add metadata information on nodes and edges:\n",
     "\n",
     "G.add_node(\"Henry_II_of_England\", age=\"65\")\n",
-    "G.add_edge(\"Eleonor_of_Aquitaine\", \"Henry_II_of_England\", year=5025)\n",
+    "G.add_edge(\"Eleonor_of_Aquitaine\", \"Henry_II_of_England\", year=5025) \n",
     "# or update info like this:\n",
-    "G[\"Eleonor_of_Aquitaine\"][\"Henry_II_of_England\"][\"weight\"] = 8\n",
+    "G[\"Eleonor_of_Aquitaine\"][\"Henry_II_of_England\"][\"weight\"] = 8 # note: we initialized the Graph-object as a basic graph\n",
+    "# Therefore all added metadata are added as additional metadata of the edge, instead of being added as additional edges (needs a MultiGraph-object)\n",
     "G[\"Eleonor_of_Aquitaine\"][\"Richard_I_of_England\"][\"sign\"] = \"positive\"\n",
     "\n",
     "print(G.nodes(data=True))\n",
@@ -193,37 +194,6 @@
     "        print(f'Nodes {e[0]} and {e[1]} are on good terms.')"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": 28,
-   "id": "6dcdff7c-f6ea-46ac-95dc-f9a2ef7fa86d",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "G[\"Eleonor_of_Aquitaine\"][\"Henry_II_of_England\"][\"sign\"] = \"negative\" "
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
-   "id": "b31ccd74-c4eb-4bca-aae9-40718b447231",
-   "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "[('Eleonor_of_Aquitaine', 'Richard_I_of_England', {'sign': 'positive'}), ('Eleonor_of_Aquitaine', 'Henry_II_of_England', {'year': 5025, 'weight': 8, 'sign': 'negative'}), ('Henry_II_of_England', 'Richard_I_of_England', {})]\n",
-      "Graph with 3 nodes and 3 edges\n"
-     ]
-    }
-   ],
-   "source": [
-    "G[\"Eleonor_of_Aquitaine\"][\"Henry_II_of_England\"][\"sign\"] = \"negative\" \n",
-    "print(G.edges(data=True))\n",
-    "print(G)"
-   ]
-  },
   {
    "cell_type": "markdown",
    "id": "13cee8e2-28df-459e-bc5d-08a7beefa411",
@@ -266,6 +236,8 @@
    "source": [
     "## Let's import a sample dataset!\n",
     "\n",
+    "**If you don't have your own data, please use the one mentioned below. If you have your own dataset, please adapt the code below accordingly.**\n",
+    "\n",
     "The sample dataset consists of sender and receivers of scholarly correspondences of early romanticism.\n",
     "\n",
     "-- The small sample dataset originates from the project [\"Correspondences of Early Romanticism. Edition -- Annotation - Network Research\"](https://gepris-extern.dfg.de/gepris/projekt/470517871?language=en), a cooperation of Universities of Marburg, Mainz, Trier, and Frankfurter Goethe Haus (2022-2025), focusing on the Jena and Berlin early Romanticism as an outstanding intellectual revolution of young German authors and scholars at the epochal threshold around 1800.)"
@@ -277,9 +249,7 @@
    "id": "bf3f9e07-9b1b-4aec-9fc8-412dc5119292",
    "metadata": {},
    "outputs": [],
-   "source": [
-    "## Import a Letter Network"
-   ]
+   "source": []
   },
   {
    "cell_type": "code",
@@ -288,8 +258,10 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "## Import a Letter Network\n",
+    "\n",
     "data = pd.read_csv(\"sender_receiver.csv\", names=[\"letter_id\", \"date\", \"sender\", \"receiver\"], header=None)\n",
-    "# names puts in new column-names, which for the original file had been ignored by 'header=None'\n",
+    "# names puts in new column-names, which for the original file have been ignored by 'header=None'\n",
     "print(data)"
    ]
   },
@@ -300,7 +272,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "#G2 = nx.DiGraph()\n",
+    "#L = nx.DiGraph()\n",
     "L = nx.MultiDiGraph() # Directed Multigraph, as there might be multiple edges between two nodes"
    ]
   },
@@ -730,12 +702,6 @@
     "### Object-based programming\n"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "id": "e71ab0c2",
-   "metadata": {},
-   "source": []
-  },
   {
    "cell_type": "code",
    "execution_count": null,
@@ -745,9 +711,9 @@
    "source": [
     "class Fall:\n",
     "\n",
-    "    def __init__(self, id):\n",
-    "        self.id = id  # about initialised variables above\n",
-    "        self.angeklagter = []\n",
+    "    def __init__(self, id): # initialize class with an id\n",
+    "        self.id = id  # this method does not need to be defined\n",
+    "        self.angeklagter = [] # all other methods need to be defined\n",
     "        self.richter = []\n",
     "        self.aktennummer = []\n",
     "    \n",
@@ -780,10 +746,10 @@
     "        self.politorientierung.append(p)\n",
     "\n",
     "\n",
-    "# Access these:\n",
+    "# Access these objects:\n",
     "Fall.id\n",
     "Fall.fallteilnehmer\n",
-    "getattr(case, fallteilnehmer) \n",
+    "getattr(running_variable, fallteilnehmer) \n",
     "\n",
     "# Fill these:\n",
     "# ... read in your data, access columns\n",