diff --git a/gtsam/slam/GeneralSFMFactor.h b/gtsam/slam/GeneralSFMFactor.h
index a49641d78..aa1d79e45 100644
--- a/gtsam/slam/GeneralSFMFactor.h
+++ b/gtsam/slam/GeneralSFMFactor.h
@@ -28,6 +28,7 @@ namespace gtsam {
 		typedef typename CamK::Value Cam;
 		typedef GeneralSFMFactor<Cfg, CamK, LmK> Self ;
 		typedef NonlinearFactor2<Cfg, CamK, LmK> Base;
+		typedef Point2 Measurement;
 
 		// shorthand for a smart pointer to a factor
 		typedef boost::shared_ptr<GeneralSFMFactor<Cfg, LmK, CamK> > shared_ptr;
diff --git a/gtsam/slam/StereoFactor.h b/gtsam/slam/StereoFactor.h
index 15c4207e9..f7e8cfb41 100644
--- a/gtsam/slam/StereoFactor.h
+++ b/gtsam/slam/StereoFactor.h
@@ -38,11 +38,9 @@ public:
 
 	// shorthand for base class type
 	typedef NonlinearFactor2<VALUES, KEY1, KEY2> Base;
-
-	// shorthand for a smart pointer to a factor
 	typedef boost::shared_ptr<GenericStereoFactor> shared_ptr;
-
 	typedef typename KEY1::Value CamPose;
+	typedef StereoPoint2 Measurement;
 
 	/**
 	 * Default constructor
@@ -101,6 +99,11 @@ public:
 		return z_;
 	}
 
+	/** return the measured */
+	inline const StereoPoint2 measured() const {
+	  return z_;
+	}
+
 private:
 	/** Serialization function */
 	friend class boost::serialization::access;