expand on descriptions of DiD, distinguishing 2x2 vs multiple observations

Author: agroutsmith

docs/source/notebooks/did_pymc_banks.ipynb

@@ -385,7 +385,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Analysis 1\n",
+    "## Analysis 1 - 2x2 DiD\n",
     "\n",
     "First we'll do an analysis just looking at data from 1930 and 1931. This way we just have a single pre-intervention and a single post-intervention measurement."
    ]
@@ -520,9 +520,9 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Analysis 2\n",
+    "## Analysis 2 - DiD with multiple pre/post observations\n",
     "\n",
-    "Now we'll do a difference in differences analysis of the full dataset."
+    "Now we'll do a difference in differences analysis of the full dataset. This approach has similarities to CITS (Comparative Interrupted Time Series) with a single control over time. Although slighyly abitrary, we distinguish between the two techniques on whether there is enough time series data for CITS to capture the time series patterns."
    ]
   },
   {