diff --git a/androidtestlib/src/com/android/test/runner/AndroidJUnitRunner.java b/androidtestlib/src/com/android/test/runner/AndroidJUnitRunner.java
index 90a3752..a932523 100644
--- a/androidtestlib/src/com/android/test/runner/AndroidJUnitRunner.java
+++ b/androidtestlib/src/com/android/test/runner/AndroidJUnitRunner.java
@@ -28,6 +28,7 @@
 import com.android.test.runner.listener.DelayInjector;
 import com.android.test.runner.listener.InstrumentationResultPrinter;
 import com.android.test.runner.listener.InstrumentationRunListener;
+import com.android.test.runner.listener.SuiteAssignmentPrinter;
 
 import org.junit.internal.TextListener;
 import org.junit.runner.JUnitCore;
@@ -121,8 +122,8 @@
  */
 public class AndroidJUnitRunner extends Instrumentation {
 
+    // constants for supported instrumentation arguments
     public static final String ARGUMENT_TEST_CLASS = "class";
-
     private static final String ARGUMENT_TEST_SIZE = "size";
     private static final String ARGUMENT_LOG_ONLY = "log";
     private static final String ARGUMENT_ANNOTATION = "annotation";
@@ -130,6 +131,9 @@
     private static final String ARGUMENT_DELAY_MSEC = "delay_msec";
     private static final String ARGUMENT_COVERAGE = "coverage";
     private static final String ARGUMENT_COVERAGE_PATH = "coverageFile";
+    private static final String ARGUMENT_SUITE_ASSIGNMENT = "suiteAssignment";
+    private static final String ARGUMENT_DEBUG = "debug";
+    // TODO: consider supporting 'count' from InstrumentationTestRunner
 
     private static final String LOG_TAG = "AndroidJUnitRunner";
 
@@ -180,7 +184,7 @@
     public void onStart() {
         prepareLooper();
 
-        if (getBooleanArgument("debug")) {
+        if (getBooleanArgument(ARGUMENT_DEBUG)) {
             Debug.waitForDebugger();
         }
 
@@ -190,11 +194,7 @@
 
         try {
             JUnitCore testRunner = new JUnitCore();
-
-            addListener(listeners, testRunner, new TextListener(writer));
-            addListener(listeners, testRunner, new InstrumentationResultPrinter(this));
-            addDelayListener(listeners, testRunner);
-            addCoverageListener(listeners, testRunner);
+            addListeners(listeners, testRunner, writer);
 
             TestRequest testRequest = buildRequest(getArguments(), writer);
             Result result = testRunner.run(testRequest.getRequest());
@@ -220,6 +220,18 @@
 
     }
 
+    private void addListeners(List<RunListener> listeners, JUnitCore testRunner,
+            PrintStream writer) {
+        if (getBooleanArgument(ARGUMENT_SUITE_ASSIGNMENT)) {
+            addListener(listeners, testRunner, new SuiteAssignmentPrinter(writer));
+        } else {
+            addListener(listeners, testRunner, new TextListener(writer));
+            addListener(listeners, testRunner, new InstrumentationResultPrinter(this));
+            addDelayListener(listeners, testRunner);
+            addCoverageListener(listeners, testRunner);
+        }
+    }
+
     private void addListener(List<RunListener> list, JUnitCore testRunner, RunListener listener) {
         list.add(listener);
         testRunner.addListener(listener);
diff --git a/androidtestlib/src/com/android/test/runner/TestRequestBuilder.java b/androidtestlib/src/com/android/test/runner/TestRequestBuilder.java
index 250a9fc..a15b70e 100644
--- a/androidtestlib/src/com/android/test/runner/TestRequestBuilder.java
+++ b/androidtestlib/src/com/android/test/runner/TestRequestBuilder.java
@@ -48,6 +48,10 @@
 
     private static final String LOG_TAG = "TestRequestBuilder";
 
+    public static final String LARGE_SIZE = "large";
+    public static final String MEDIUM_SIZE = "medium";
+    public static final String SMALL_SIZE = "small";
+
     private String[] mApkPaths;
     private TestLoader mTestLoader;
     private Filter mFilter = new AnnotationExclusionFilter(Suppress.class);
@@ -154,11 +158,11 @@
      * @param testSize
      */
     public void addTestSizeFilter(String testSize) {
-        if ("small".equals(testSize)) {
+        if (SMALL_SIZE.equals(testSize)) {
             mFilter = mFilter.intersect(new AnnotationInclusionFilter(SmallTest.class));
-        } else if ("medium".equals(testSize)) {
+        } else if (MEDIUM_SIZE.equals(testSize)) {
             mFilter = mFilter.intersect(new AnnotationInclusionFilter(MediumTest.class));
-        } else if ("large".equals(testSize)) {
+        } else if (LARGE_SIZE.equals(testSize)) {
             mFilter = mFilter.intersect(new AnnotationInclusionFilter(LargeTest.class));
         } else {
             Log.e(LOG_TAG, String.format("Unrecognized test size '%s'", testSize));
diff --git a/androidtestlib/src/com/android/test/runner/listener/SuiteAssignmentPrinter.java b/androidtestlib/src/com/android/test/runner/listener/SuiteAssignmentPrinter.java
new file mode 100644
index 0000000..ac4aa2c
--- /dev/null
+++ b/androidtestlib/src/com/android/test/runner/listener/SuiteAssignmentPrinter.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.test.runner.listener;
+
+import com.android.test.runner.TestRequestBuilder;
+
+import org.junit.runner.Description;
+import org.junit.runner.notification.Failure;
+import org.junit.runner.notification.RunListener;
+
+import java.io.PrintStream;
+
+/**
+ * This class measures the elapsed run time of each test, and used it to report back to the user
+ * which suite ({@link SmallSuite}, {@link MediumSuite}, {@link LargeSuite}) the test should belong
+ * to.
+ */
+public class SuiteAssignmentPrinter extends RunListener {
+    /**
+     * This constant defines the maximum allowed runtime (in ms) for a test included in the "small"
+     * suite. It is used to make an educated guess at what suite an unlabeled test belongs to.
+     */
+    private static final float SMALL_SUITE_MAX_RUNTIME = 100;
+
+    /**
+     * This constant defines the maximum allowed runtime (in ms) for a test included in the "medium"
+     * suite. It is used to make an educated guess at what suite an unlabeled test belongs to.
+     */
+    private static final float MEDIUM_SUITE_MAX_RUNTIME = 1000;
+
+    private final PrintStream mWriter;
+
+    public SuiteAssignmentPrinter(PrintStream writer) {
+        mWriter = writer;
+    }
+
+    private long mStartTime;
+    private boolean mTimingValid;
+
+    @Override
+    public void testStarted(Description description) throws Exception {
+        mTimingValid = true;
+        mStartTime = System.currentTimeMillis();
+    }
+
+    @Override
+    public void testFinished(Description description) throws Exception {
+        long runTime;
+        String assignmentSuite;
+        long endTime = System.currentTimeMillis();
+
+        if (!mTimingValid || mStartTime < 0) {
+            assignmentSuite = "NA";
+            runTime = -1;
+        } else {
+            runTime = endTime - mStartTime;
+            if (runTime < SMALL_SUITE_MAX_RUNTIME) {
+                assignmentSuite = TestRequestBuilder.SMALL_SIZE;
+            } else if (runTime < MEDIUM_SUITE_MAX_RUNTIME) {
+                assignmentSuite = TestRequestBuilder.MEDIUM_SIZE;
+            } else {
+                assignmentSuite = TestRequestBuilder.LARGE_SIZE;
+            }
+        }
+        // Clear mStartTime so that we can verify that it gets set next time.
+        mStartTime = -1;
+
+        mWriter.printf("%s#%s\n" + "in %s suite\n" + "runTime: %d ms\n",
+                        description.getClassName(), description.getMethodName(), assignmentSuite,
+                        runTime);
+    }
+
+    @Override
+    public void testFailure(Failure failure) throws Exception {
+        mTimingValid = false;
+    }
+
+    @Override
+    public void testAssumptionFailure(Failure failure) {
+        mTimingValid = false;
+    }
+
+    @Override
+    public void testIgnored(Description description) throws Exception {
+        mTimingValid = false;
+    }
+}
diff --git a/androidtestlib/tests/src/com/android/test/MyAndroidTestCase.java b/androidtestlib/tests/src/com/android/test/MyAndroidTestCase.java
index 1e328ac..f48337e 100644
--- a/androidtestlib/tests/src/com/android/test/MyAndroidTestCase.java
+++ b/androidtestlib/tests/src/com/android/test/MyAndroidTestCase.java
@@ -17,6 +17,7 @@
 
 import android.content.Context;
 import android.test.AndroidTestCase;
+import android.util.Log;
 
 /**
  * Placeholder test to verify {@link Context} gets injected to {@link AndroidTestCase}.
@@ -24,4 +25,8 @@
 public class MyAndroidTestCase extends AndroidTestCase {
 
     // rely on testCaseSetupProperly to test for context
+
+    public MyAndroidTestCase() {
+        Log.i("MyAndroidTestCase", "I'm created");
+    }
 }