diff --git a/src/main/java/be/cylab/java/wowa/training/SolutionDistance.java b/src/main/java/be/cylab/java/wowa/training/SolutionDistance.java
index b0437b7c523020bfab999a33930ee46d1742c87e..bca33207705f6a98f77544941217125fef00a93a 100644
--- a/src/main/java/be/cylab/java/wowa/training/SolutionDistance.java
+++ b/src/main/java/be/cylab/java/wowa/training/SolutionDistance.java
@@ -41,7 +41,7 @@ public class SolutionDistance implements Comparable<SolutionDistance> {
      * @param data
      * @param expected
      */
-    void computeScoreTo(final List<double[]> data, final double[] expected) {
+    final void computeScoreTo(final List<double[]> data, final double[] expected) {
 
         this.distance = 0;
         for (int i = 0; i < data.size(); i++) {
@@ -58,7 +58,7 @@ public class SolutionDistance implements Comparable<SolutionDistance> {
     /**
      * @param probability
      */
-    void randomlyMutateWithProbability(final double probability) {
+    final void randomlyMutateWithProbability(final double probability) {
         double tos = Math.random();
         if (tos > probability) {
             // do nothing
@@ -81,7 +81,7 @@ public class SolutionDistance implements Comparable<SolutionDistance> {
 
     /**
      * @param solution
-     * @return
+     * @return int
      */
     @Override
     public int compareTo(final SolutionDistance solution) {
@@ -92,7 +92,7 @@ public class SolutionDistance implements Comparable<SolutionDistance> {
     /**
      *
      */
-    void normalize() {
+    final void normalize() {
         this.weights_w = Utils.normalizeWeights(this.weights_w);
         this.weights_p = Utils.normalizeWeights(this.weights_p);
     }
@@ -100,15 +100,15 @@ public class SolutionDistance implements Comparable<SolutionDistance> {
     /**
      * @return
      */
-    double getDistance() {
+    final double getDistance() {
         return distance;
     }
 
-    double[] getWeightsW() {
+    final double[] getWeightsW() {
         return this.weights_w;
     }
 
-    double[] getWeightsP() {
+    final double[] getWeightsP() {
         return this.weights_p;
     }
 }