diff --git a/java/src/org/broadinstitute/sting/playground/gatk/walkers/MultiSampleCallerAccuracyTest.java b/java/src/org/broadinstitute/sting/playground/gatk/walkers/MultiSampleCallerAccuracyTest.java
new file mode 100644
index 000000000..c1a8f3e70
--- /dev/null
+++ b/java/src/org/broadinstitute/sting/playground/gatk/walkers/MultiSampleCallerAccuracyTest.java
@@ -0,0 +1,92 @@
+
+package org.broadinstitute.sting.playground.gatk.walkers;
+
+import net.sf.samtools.SAMFileHeader;
+import net.sf.samtools.SAMReadGroupRecord;
+import net.sf.samtools.SAMRecord;
+import org.broadinstitute.sting.gatk.GenomeAnalysisEngine;
+import org.broadinstitute.sting.gatk.LocusContext;
+import org.broadinstitute.sting.gatk.refdata.*;
+import org.broadinstitute.sting.gatk.walkers.LocusWalker;
+import org.broadinstitute.sting.playground.utils.AlleleFrequencyEstimate;
+import org.broadinstitute.sting.playground.utils.*;
+import org.broadinstitute.sting.utils.*;
+import org.broadinstitute.sting.utils.ReadBackedPileup;
+import org.broadinstitute.sting.utils.cmdLine.Argument;
+
+import java.util.*;
+import java.util.zip.*;
+import java.io.*;
+
+// Beta iterative multi-sample caller
+// j.maguire 6-11-2009
+
+public class MultiSampleCallerAccuracyTest extends MultiSampleCaller
+{
+    @Argument(required=false, shortName="lod_threshold", doc="") public double LOD_THRESHOLD = 1e-6;
+
+
+    public void initialize() 
+	{
+		this.DISCOVERY_OUTPUT = "/dev/null";
+		this.INDIVIDUAL_OUTPUT = "/dev/null";
+		super.initialize();
+	}
+
+    public MultiSampleCallResult map(RefMetaDataTracker tracker, char ref, LocusContext context) 
+	{
+        HapMapGenotypeROD hapmap = (HapMapGenotypeROD)tracker.lookup("hapmap", null);
+
+		MultiSampleCallResult call_result = super.map(tracker, ref, context);
+		EM_Result em_result = call_result.em_result;
+
+		// Compute individual accuracy.
+		double n_calls = 0;
+		double n_correct = 0;
+		for (int i = 0; i < em_result.sample_names.length; i++)
+		{
+			String sample_name = em_result.sample_names[i];
+			String hyp_genotype = em_result.genotype_likelihoods[i].BestGenotype();
+			String ref_genotype = hapmap.get(sample_name);
+			double lod = em_result.genotype_likelihoods[i].LodVsNextBest();
+
+			if ((lod > LOD_THRESHOLD) && (ref_genotype != null))
+			{
+				n_calls += 1;
+				if (hyp_genotype.equals(ref_genotype))
+				{
+					n_correct += 1;
+				}
+			}
+
+		}
+
+		out.printf("%s %.0f %.0f %.2f%%\n", 
+						context.getLocation(), 
+						n_calls, 
+						n_correct, 
+						100.0*n_correct / n_calls);
+
+		return call_result;
+	}
+
+    public void onTraversalDone(String sum) 
+	{
+		out.println("MultiSampleCallerAccuracyTest done.");
+		return;
+	}
+
+    public String reduceInit() 
+	{
+		return super.reduceInit();
+	}
+
+    public String reduce(MultiSampleCallResult record, String sum) 
+	{
+		return super.reduce(record, sum);
+	}
+
+	// END Walker Interface Functions
+	/////////
+
+}