diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9118830..e6a556b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -18,14 +18,27 @@
 General questions should go to the [golang-nuts mailing list](https://groups.google.com/group/golang-nuts) instead of the issue tracker.
 The gophers there will answer or ask you to file an issue if you've tripped over a bug.
 
+## Verifying changes during development
+
+In order to verify changes to the slides or code examples while developing
+locally compile with your local toolchain:
+
+	$ go install golang.org/x/tour/gotour
+	$ $GOPATH/bin/gotour
+
 ## Running the App Engine version locally
 
-To view your changes while developing locally, install the
-[Go App Engine SDK](https://cloud.google.com/appengine/downloads?hl=en) and then:
+To view the App Engine version of the slides while developing locally, install
+the [Go App Engine SDK](https://cloud.google.com/appengine/downloads?hl=en)
+and then:
 
 	$ cd $GOPATH/src/golang.org/x/tour
 	$ $SDK_PATH/dev_appserver.py .
 
+The App Engine version runs code examples against the service at play.golang.org.
+To verify changes to the code examples you must use your local toolchain to compile
+and run `gotour` locally.
+
 ## Contributing code
 
 Please read the [Contribution Guidelines](https://golang.org/doc/contribute.html)