diff --git a/ui/ui-layout/api/0.1.0-dev14.txt b/ui/ui-layout/api/0.1.0-dev14.txt
index 6abd57d..efa6a30 100644
--- a/ui/ui-layout/api/0.1.0-dev14.txt
+++ b/ui/ui-layout/api/0.1.0-dev14.txt
@@ -154,17 +154,17 @@
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createAbsoluteRightBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createBottomBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createEndBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop-ipo6vVg(float offset);
     method public final void createHorizontalChain(androidx.ui.layout.ConstrainedLayoutReference![] elements, androidx.ui.layout.ChainStyle chainStyle = ChainStyle.Spread);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createStartBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
diff --git a/ui/ui-layout/api/current.txt b/ui/ui-layout/api/current.txt
index 6abd57d..efa6a30 100644
--- a/ui/ui-layout/api/current.txt
+++ b/ui/ui-layout/api/current.txt
@@ -154,17 +154,17 @@
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createAbsoluteRightBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createBottomBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createEndBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop-ipo6vVg(float offset);
     method public final void createHorizontalChain(androidx.ui.layout.ConstrainedLayoutReference![] elements, androidx.ui.layout.ChainStyle chainStyle = ChainStyle.Spread);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createStartBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
diff --git a/ui/ui-layout/api/public_plus_experimental_0.1.0-dev14.txt b/ui/ui-layout/api/public_plus_experimental_0.1.0-dev14.txt
index 6abd57d..efa6a30 100644
--- a/ui/ui-layout/api/public_plus_experimental_0.1.0-dev14.txt
+++ b/ui/ui-layout/api/public_plus_experimental_0.1.0-dev14.txt
@@ -154,17 +154,17 @@
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createAbsoluteRightBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createBottomBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createEndBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop-ipo6vVg(float offset);
     method public final void createHorizontalChain(androidx.ui.layout.ConstrainedLayoutReference![] elements, androidx.ui.layout.ChainStyle chainStyle = ChainStyle.Spread);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createStartBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
diff --git a/ui/ui-layout/api/public_plus_experimental_current.txt b/ui/ui-layout/api/public_plus_experimental_current.txt
index 6abd57d..efa6a30 100644
--- a/ui/ui-layout/api/public_plus_experimental_current.txt
+++ b/ui/ui-layout/api/public_plus_experimental_current.txt
@@ -154,17 +154,17 @@
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createAbsoluteRightBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createBottomBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createEndBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop-ipo6vVg(float offset);
     method public final void createHorizontalChain(androidx.ui.layout.ConstrainedLayoutReference![] elements, androidx.ui.layout.ChainStyle chainStyle = ChainStyle.Spread);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createStartBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
diff --git a/ui/ui-layout/api/restricted_0.1.0-dev14.txt b/ui/ui-layout/api/restricted_0.1.0-dev14.txt
index 6abd57d..efa6a30 100644
--- a/ui/ui-layout/api/restricted_0.1.0-dev14.txt
+++ b/ui/ui-layout/api/restricted_0.1.0-dev14.txt
@@ -154,17 +154,17 @@
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createAbsoluteRightBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createBottomBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createEndBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop-ipo6vVg(float offset);
     method public final void createHorizontalChain(androidx.ui.layout.ConstrainedLayoutReference![] elements, androidx.ui.layout.ChainStyle chainStyle = ChainStyle.Spread);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createStartBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
diff --git a/ui/ui-layout/api/restricted_current.txt b/ui/ui-layout/api/restricted_current.txt
index 6abd57d..efa6a30 100644
--- a/ui/ui-layout/api/restricted_current.txt
+++ b/ui/ui-layout/api/restricted_current.txt
@@ -154,17 +154,17 @@
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createAbsoluteRightBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createBottomBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createEndBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteLeft-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromAbsoluteRight-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromBottom-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromEnd-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createGuidelineFromStart-ipo6vVg(float offset);
-    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float percent);
+    method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop(float fraction);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.HorizontalAnchor createGuidelineFromTop-ipo6vVg(float offset);
     method public final void createHorizontalChain(androidx.ui.layout.ConstrainedLayoutReference![] elements, androidx.ui.layout.ChainStyle chainStyle = ChainStyle.Spread);
     method public final androidx.ui.layout.ConstraintLayoutBaseScope.VerticalAnchor createStartBarrier-AuEMxJ0(androidx.ui.layout.ConstrainedLayoutReference![] elements, float margin = 0.dp);
diff --git a/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/ConstraintLayoutTest.kt b/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/ConstraintLayoutTest.kt
index 294e39c..48a796e 100644
--- a/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/ConstraintLayoutTest.kt
+++ b/ui/ui-layout/src/androidTest/java/androidx/ui/layout/test/ConstraintLayoutTest.kt
@@ -319,7 +319,7 @@
                         position[0].value = it.globalPosition
                     }
                 )
-                val half = createGuidelineFromAbsoluteLeft(percent = 0.5f)
+                val half = createGuidelineFromAbsoluteLeft(fraction = 0.5f)
                 Box(Modifier
                     .constrainAs(box1) {
                         start.linkTo(half, margin = offset.toDp())
@@ -380,7 +380,7 @@
                         centerTo(parent)
                     }
 
-                    val half = createGuidelineFromAbsoluteLeft(percent = 0.5f)
+                    val half = createGuidelineFromAbsoluteLeft(fraction = 0.5f)
                     constrain(box1) {
                         start.linkTo(half, margin = offset.toDp())
                         bottom.linkTo(box0.top)
@@ -441,7 +441,7 @@
                         position[0].value = it.globalPosition
                     }
                 )
-                val half = createGuidelineFromAbsoluteLeft(percent = 0.5f)
+                val half = createGuidelineFromAbsoluteLeft(fraction = 0.5f)
                 Box(Modifier
                     .constrainAs(box1) {
                         start.linkTo(half, margin = offset.toDp())
diff --git a/ui/ui-layout/src/main/java/androidx/ui/layout/ConstraintLayout.kt b/ui/ui-layout/src/main/java/androidx/ui/layout/ConstraintLayout.kt
index abdfe3db..a10d348 100644
--- a/ui/ui-layout/src/main/java/androidx/ui/layout/ConstraintLayout.kt
+++ b/ui/ui-layout/src/main/java/androidx/ui/layout/ConstraintLayout.kt
@@ -233,15 +233,17 @@
 
     /**
      * Creates a guideline at a specific offset from the start of the [ConstraintLayout].
+     * A [fraction] of 0f will correspond to the start of the [ConstraintLayout], while 1f will
+     * correspond to the end.
      */
-    fun createGuidelineFromStart(percent: Float): VerticalAnchor {
+    fun createGuidelineFromStart(fraction: Float): VerticalAnchor {
         val tag = createTag()
         tasks.add { state ->
             state.verticalGuideline(tag).apply {
                 if (state.layoutDirection == LayoutDirection.Ltr) {
-                    percent(percent)
+                    percent(fraction)
                 } else {
-                    percent(1f - percent)
+                    percent(1f - fraction)
                 }
             }
         }
@@ -249,12 +251,14 @@
     }
 
     /**
-     * Creates a guideline at a width percentage from the left of the [ConstraintLayout].
+     * Creates a guideline at a width fraction from the left of the [ConstraintLayout].
+     * A [fraction] of 0f will correspond to the left of the [ConstraintLayout], while 1f will
+     * correspond to the right.
      */
     // TODO(popam, b/157781990): this is not really percentage
-    fun createGuidelineFromAbsoluteLeft(percent: Float): VerticalAnchor {
+    fun createGuidelineFromAbsoluteLeft(fraction: Float): VerticalAnchor {
         val tag = createTag()
-        tasks.add { state -> state.verticalGuideline(tag).apply { percent(percent) } }
+        tasks.add { state -> state.verticalGuideline(tag).apply { percent(fraction) } }
         return VerticalAnchor(tag, 0)
     }
 
@@ -282,16 +286,20 @@
 
     /**
      * Creates a guideline at a width percentage from the end of the [ConstraintLayout].
+     * A [fraction] of 0f will correspond to the end of the [ConstraintLayout], while 1f will
+     * correspond to the start.
      */
-    fun createGuidelineFromEnd(percent: Float): VerticalAnchor {
-        return createGuidelineFromStart(1f - percent)
+    fun createGuidelineFromEnd(fraction: Float): VerticalAnchor {
+        return createGuidelineFromStart(1f - fraction)
     }
 
     /**
      * Creates a guideline at a width percentage from the right of the [ConstraintLayout].
+     * A [fraction] of 0f will correspond to the right of the [ConstraintLayout], while 1f will
+     * correspond to the left.
      */
-    fun createGuidelineFromAbsoluteRight(percent: Float): VerticalAnchor {
-        return createGuidelineFromAbsoluteLeft(1f - percent)
+    fun createGuidelineFromAbsoluteRight(fraction: Float): VerticalAnchor {
+        return createGuidelineFromAbsoluteLeft(1f - fraction)
     }
 
     /**
@@ -305,10 +313,12 @@
 
     /**
      * Creates a guideline at a height percentage from the top of the [ConstraintLayout].
+     * A [fraction] of 0f will correspond to the top of the [ConstraintLayout], while 1f will
+     * correspond to the bottom.
      */
-    fun createGuidelineFromTop(percent: Float): HorizontalAnchor {
+    fun createGuidelineFromTop(fraction: Float): HorizontalAnchor {
         val tag = createTag()
-        tasks.add { state -> state.horizontalGuideline(tag).apply { percent(percent) } }
+        tasks.add { state -> state.horizontalGuideline(tag).apply { percent(fraction) } }
         return HorizontalAnchor(tag, 0)
     }
 
@@ -323,9 +333,11 @@
 
     /**
      * Creates a guideline at a height percentage from the bottom of the [ConstraintLayout].
+     * A [fraction] of 0f will correspond to the bottom of the [ConstraintLayout], while 1f will
+     * correspond to the top.
      */
-    fun createGuidelineFromBottom(percent: Float): HorizontalAnchor {
-        return createGuidelineFromTop(1f - percent)
+    fun createGuidelineFromBottom(fraction: Float): HorizontalAnchor {
+        return createGuidelineFromTop(1f - fraction)
     }
 
     /**