diff --git a/lucene/classification/src/java/org/apache/lucene/classification/utils/ConfusionMatrixGenerator.java b/lucene/classification/src/java/org/apache/lucene/classification/utils/ConfusionMatrixGenerator.java
index 3dd8ba83d04..65de8015f20 100644
--- a/lucene/classification/src/java/org/apache/lucene/classification/utils/ConfusionMatrixGenerator.java
+++ b/lucene/classification/src/java/org/apache/lucene/classification/utils/ConfusionMatrixGenerator.java
@@ -175,7 +175,7 @@ public class ConfusionMatrixGenerator {
     public double getPrecision(String klass) {
       Map<String, Long> classifications = linearizedMatrix.get(klass);
       double tp = 0;
-      double fp = 0;
+      double den = 0; // tp + fp
       if (classifications != null) {
         for (Map.Entry<String, Long> entry : classifications.entrySet()) {
           if (klass.equals(entry.getKey())) {
@@ -184,11 +184,11 @@ public class ConfusionMatrixGenerator {
         }
         for (Map<String, Long> values : linearizedMatrix.values()) {
           if (values.containsKey(klass)) {
-            fp += values.get(klass);
+            den += values.get(klass);
           }
         }
       }
-      return tp > 0 ? tp / (tp + fp) : 0;
+      return tp > 0 ? tp / den : 0;
     }
 
     /**
@@ -246,7 +246,7 @@ public class ConfusionMatrixGenerator {
       if (this.accuracy == -1) {
         double tp = 0d;
         double tn = 0d;
-        double fp = 0d;
+        double tfp = 0d; // tp + fp
         double fn = 0d;
         for (Map.Entry<String, Map<String, Long>> classification : linearizedMatrix.entrySet()) {
           String klass = classification.getKey();
@@ -259,63 +259,46 @@ public class ConfusionMatrixGenerator {
           }
           for (Map<String, Long> values : linearizedMatrix.values()) {
             if (values.containsKey(klass)) {
-              fp += values.get(klass);
+              tfp += values.get(klass);
             } else {
               tn++;
             }
           }
 
         }
-        this.accuracy = (tp + tn) / (fp + fn + tp + tn);
+        this.accuracy = (tp + tn) / (tfp + fn + tn);
       }
       return this.accuracy;
     }
 
     /**
-     * get the precision (see {@link #getPrecision(String)}) over all the classes.
+     * get the macro averaged precision (see {@link #getPrecision(String)}) over all the classes.
      *
-     * @return the precision as computed from the whole confusion matrix
+     * @return the macro averaged precision as computed from the confusion matrix
      */
     public double getPrecision() {
-      double tp = 0;
-      double fp = 0;
+      double p = 0;
       for (Map.Entry<String, Map<String, Long>> classification : linearizedMatrix.entrySet()) {
         String klass = classification.getKey();
-        for (Map.Entry<String, Long> entry : classification.getValue().entrySet()) {
-          if (klass.equals(entry.getKey())) {
-            tp += entry.getValue();
-          }
-        }
-        for (Map<String, Long> values : linearizedMatrix.values()) {
-          if (values.containsKey(klass)) {
-            fp += values.get(klass);
-          }
-        }
+        p += getPrecision(klass);
       }
 
-      return tp > 0 ? tp / (tp + fp) : 0;
+      return p / linearizedMatrix.size();
     }
 
     /**
-     * get the recall (see {@link #getRecall(String)}) over all the classes
+     * get the macro averaged recall (see {@link #getRecall(String)}) over all the classes
      *
-     * @return the recall as computed from the whole confusion matrix
+     * @return the recall as computed from the confusion matrix
      */
     public double getRecall() {
-      double tp = 0;
-      double fn = 0;
+      double r = 0;
       for (Map.Entry<String, Map<String, Long>> classification : linearizedMatrix.entrySet()) {
         String klass = classification.getKey();
-        for (Map.Entry<String, Long> entry : classification.getValue().entrySet()) {
-          if (klass.equals(entry.getKey())) {
-            tp += entry.getValue();
-          } else {
-            fn += entry.getValue();
-          }
-        }
+        r += getRecall(klass);
       }
 
-      return tp + fn > 0 ? tp / (tp + fn) : 0;
+      return r / linearizedMatrix.size();
     }
 
     @Override
diff --git a/lucene/classification/src/java/org/apache/lucene/classification/utils/DatasetSplitter.java b/lucene/classification/src/java/org/apache/lucene/classification/utils/DatasetSplitter.java
index c1c8ad19ee6..fbc57b93eb2 100644
--- a/lucene/classification/src/java/org/apache/lucene/classification/utils/DatasetSplitter.java
+++ b/lucene/classification/src/java/org/apache/lucene/classification/utils/DatasetSplitter.java
@@ -30,7 +30,6 @@ import org.apache.lucene.index.IndexWriterConfig;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.SortedDocValues;
-import org.apache.lucene.index.Terms;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.MatchAllDocsQuery;
 import org.apache.lucene.search.ScoreDoc;