diff --git a/introduction.tex b/introduction.tex
index af2f04e..f0ed8be 100644
--- a/introduction.tex
+++ b/introduction.tex
@@ -81,4 +81,4 @@ measure and discussion of how each could be measured and how useful it might
 be. In Section~\ref{sec-results} we present at formulating a value measure
 based on content delivered through the video display and audio output---an
 attempt that we consider a failure based on the result of a user survey, but
-one that we hope sheds light on how difficult this challenge may be. 
+one that we hope sheds light on how difficult this challenge may be.