diff --git a/lib/interaction.html b/lib/interaction.html
index 1fb1b04..ab7d9d7 100644
--- a/lib/interaction.html
+++ b/lib/interaction.html
@@ -23,7 +23,7 @@ a single delegate pattern.
 <p>The main differences are that <code>PointerEvent</code> are fired for each
 touch point, whereas the <code>TouchEvent</code> collects multiple
 <code>TouchPoints</code> into a single event. The basic PointMap and Interaction
-classes unify this behavior by collection all contact points regardless
+classes unify this behavior by collecting all contact points regardless
 of their original mouse, touch, or pointer events.</p>
 <h2>
     Point Maps