diff --git a/README.md b/README.md
index c39b027..d91a958 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,15 @@ The csv file is expected to have two columns (variable name, description).
 
 3-Clause BSD (see LICENSE)
 
+## Tests
+
+The `test/` subdirectory contains a script to generate a synthetic data set, an integration test for the codebooks package, and a benchmark script used to test performance optimizations. You can run these with:
+
+    cd test
+    python dataset.py
+    codebooks dataset.csv
+    python benchmark.py
+
 ## Authors
 
 Mark Howison  
diff --git a/src/codebooks/html.py b/src/codebooks/html.py
index a89b2b7..7075fa5 100644
--- a/src/codebooks/html.py
+++ b/src/codebooks/html.py
@@ -137,7 +137,7 @@ def set_html(self):
         )]
 
         if self.var.type == "Unique Key" or self.var.type == "Empty":
-            self.html.appned("<td colspan=7></td>")
+            self.html.append("<td colspan=7></td>")
         elif self.var.type == "Constant":
             self.html.append("""
                 <td colspan=6><strong>{}</strong></td>