diff --git a/IPython/html/static/widgets/js/widget.js b/IPython/html/static/widgets/js/widget.js
index 9fe52eb..f8b31aa 100644
--- a/IPython/html/static/widgets/js/widget.js
+++ b/IPython/html/static/widgets/js/widget.js
@@ -266,7 +266,12 @@ define(["widgets/js/manager",
}
},
- on_bulk_change: function(keys, callback, context) {
+ on_change: function(keys, callback, context) {
+ // on_change(["key1", "key2"], foo, context) differs from
+ // on("change:key1 change:key2", foo, context).
+ // If the widget attributes key1 and key2 are both modified,
+ // the second form will result in foo being called twice
+ // while the first will call foo only once.
this.on('change', function() {
if (keys.some(this.hasChanged, this)) {
callback.apply(context);