diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/MaterialFeatureVectorSummaryLoader.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/MaterialFeatureVectorSummaryLoader.java
index b58b4327ade4091298b46389cc534e5c5304fa4e..97aa99f268a53e649f1406c3ea87474b27271217 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/MaterialFeatureVectorSummaryLoader.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/MaterialFeatureVectorSummaryLoader.java
@@ -184,7 +184,7 @@ public class MaterialFeatureVectorSummaryLoader extends ExperimentFeatureVectorS
             return null;
         }
         List<IWellData> materialWellDataList =
-                filterMaterialWells(wellDataCollection.getWellDataList(), materialId);
+                filterWellsByMaterial(wellDataCollection.getWellDataList(), materialId);
         GroupByMap<Double, IWellData> subgroupMap = groupBySubgroup(materialWellDataList);
 
         List<MaterialReplicaSubgroupFeatureVector> subgroups = Collections.emptyList();
@@ -324,7 +324,7 @@ public class MaterialFeatureVectorSummaryLoader extends ExperimentFeatureVectorS
         return subgroupMap.getKeys().size() == 1 && subgroupMap.getKeys().contains(null);
     }
 
-    private static List<IWellData> filterMaterialWells(List<IWellData> wellDataList,
+    private static List<IWellData> filterWellsByMaterial(List<IWellData> wellDataList,
             final TechId materialId)
     {
         return CollectionUtils.filter(wellDataList, new ICollectionFilter<IWellData>()
diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/dto/IWellData.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/dto/IWellData.java
index 2b8e19507853882ce14dba0728b41e804987ede3..48878136684c891dfafc16ac4a42c4f369c3b1ba 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/dto/IWellData.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/server/logic/dto/IWellData.java
@@ -38,9 +38,9 @@ public interface IWellData
     Sample getWell();
 
     /**
-     * Material in the well which allowed to find replicates.<br>
+     * Material in the well which allowed to find replicates (e.g. gene or compound).<br>
      * Note: if the replicaId is the same for two wellData then the returned material is also the
-     * same
+     * same.
      */
     Material getMaterial();