diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/ConditionWidget.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/ConditionWidget.java
index dd3002b..03c1f83 100644
--- a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/ConditionWidget.java
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/ConditionWidget.java
@@ -10,6 +10,9 @@ import org.gcube.portlets.user.td.expressionwidget.client.operation.Operation;
 import org.gcube.portlets.user.td.expressionwidget.client.operation.OperationProperties;
 import org.gcube.portlets.user.td.expressionwidget.client.operation.OperationsStore;
 import org.gcube.portlets.user.td.expressionwidget.client.resources.ExpressionResources;
+import org.gcube.portlets.user.td.expressionwidget.client.threshold.Threshold;
+import org.gcube.portlets.user.td.expressionwidget.client.threshold.ThresholdProperties;
+import org.gcube.portlets.user.td.expressionwidget.client.threshold.ThresholdStore;
 import org.gcube.portlets.user.td.expressionwidget.shared.condition.ConditionTypeMap;
 import org.gcube.portlets.user.td.expressionwidget.shared.exception.ConditionTypeMapException;
 import org.gcube.portlets.user.td.gwtservice.shared.tr.ColumnData;
@@ -61,6 +64,8 @@ public class ConditionWidget extends SimpleContainer {
 	protected String itemIdSecondArg;
 	protected String itemIdFirstArgDate;
 	protected String itemIdSecondArgDate;
+	protected String itemIdComboThreshold;
+	
 	protected String itemIdBtnAdd;
 	protected String itemIdBtnDel;
 	protected VerticalLayoutContainer vert;
@@ -92,6 +97,7 @@ public class ConditionWidget extends SimpleContainer {
 		itemIdSecondArg = "SecondArg" + column.getName();
 		itemIdFirstArgDate = "FirstArgDate" + column.getName();
 		itemIdSecondArgDate = "SecondArgDate" + column.getName();
+		itemIdComboThreshold = "ComboThreshold" + column.getName();
 		itemIdBtnAdd = "BtnAdd" + column.getName();
 		itemIdBtnDel = "BtnDel" + column.getName();
 
@@ -122,7 +128,7 @@ public class ConditionWidget extends SimpleContainer {
 		groupMatch.setValue(radioAll);
 
 		vert = new VerticalLayoutContainer();
-		//vert.setScrollMode(ScrollMode.AUTO); Set In GXT 3.0.1
+		// vert.setScrollMode(ScrollMode.AUTO); Set In GXT 3.0.1
 		vert.setAdjustForScroll(true);
 
 		setup();
@@ -156,6 +162,33 @@ public class ConditionWidget extends SimpleContainer {
 		secondArgDate.setItemId(itemIdSecondArgDate);
 		secondArgDate.setVisible(false);
 
+		// Combo Similarity and Levenshtein threshold
+		ThresholdProperties propsThreshold = GWT
+				.create(ThresholdProperties.class);
+		Log.debug("Props: " + propsThreshold);
+		final ListStore<Threshold> storeThreshold = new ListStore<Threshold>(
+				propsThreshold.id());
+		Log.debug("StoreThreshold: " + storeThreshold);
+		storeThreshold.addAll(ThresholdStore.thresholdsLevenshtein);
+
+		Log.debug("StoreThreshold created");
+		final ComboBox<Threshold> comboThreshold = new ComboBox<Threshold>(
+				storeThreshold, propsThreshold.label());
+
+		Log.debug("Combo Threshold created");
+
+		comboThreshold.setEmptyText("Select a threshold...");
+		comboThreshold.setItemId(itemIdComboThreshold);
+		comboThreshold.setWidth("100px");
+		comboThreshold.setEditable(false);
+		comboThreshold.setTriggerAction(TriggerAction.ALL);
+		comboThreshold.setVisible(false);
+
+		final HTML thresholdText = new HTML(
+				"<div style='vertical-align:middle; margin-left:2px;margin-right:2px;margin-top:4px;'>Threshold:</div>");
+		thresholdText.setVisible(false);
+		
+		// Button
 		final IconButton btnAdd = new IconButton();
 		btnAdd.setItemId(itemIdBtnAdd);
 		btnAdd.setIcon(ExpressionResources.INSTANCE.add());
@@ -195,6 +228,7 @@ public class ConditionWidget extends SimpleContainer {
 		});
 		btnDel.setVisible(false);
 
+		// Operation
 		OperationProperties props = GWT.create(OperationProperties.class);
 		Log.debug("Props: " + props);
 		ListStore<Operation> storeOp = new ListStore<Operation>(props.id());
@@ -233,15 +267,19 @@ public class ConditionWidget extends SimpleContainer {
 					case NOT_MATCH_REGEX:
 					case IN:
 					case NOT_IN:
-					case SOUNDEX:	
+					case SOUNDEX:
 						if (column.getDataTypeName().compareTo("Date") == 0) {
 							firstArgDate.setVisible(true);
 							andText.setVisible(false);
 							secondArgDate.setVisible(false);
+							comboThreshold.setVisible(false);
+							thresholdText.setVisible(false);
 						} else {
 							firstArg.setVisible(true);
 							andText.setVisible(false);
 							secondArg.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						}
 						btnAdd.setVisible(true);
 						btnDel.setVisible(true);
@@ -252,10 +290,66 @@ public class ConditionWidget extends SimpleContainer {
 							firstArgDate.setVisible(false);
 							andText.setVisible(false);
 							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						} else {
 							firstArg.setVisible(true);
 							andText.setVisible(true);
 							secondArg.setVisible(true);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
+						}
+						btnAdd.setVisible(true);
+						btnDel.setVisible(true);
+						break;
+					case LEVENSHTEIN:
+						if (column.getDataTypeName().compareTo("Date") == 0) {
+							firstArgDate.setVisible(false);
+							andText.setVisible(false);
+							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
+						} else {
+							firstArg.setVisible(true);
+							andText.setVisible(false);
+							secondArg.setVisible(false);
+							thresholdText.setVisible(true);
+							storeThreshold.clear();
+							storeThreshold
+									.addAll(ThresholdStore.thresholdsLevenshtein);
+							storeThreshold.commitChanges();
+							comboThreshold.clear();
+							comboThreshold.reset();
+							comboThreshold.setVisible(true);
+							comboThreshold.setValue(ThresholdStore
+									.defaultThresholdLevenshtein());
+
+						}
+						btnAdd.setVisible(true);
+						btnDel.setVisible(true);
+						break;
+					case SIMILARITY:
+						if (column.getDataTypeName().compareTo("Date") == 0) {
+							firstArgDate.setVisible(false);
+							andText.setVisible(false);
+							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
+						} else {
+							firstArg.setVisible(true);
+							andText.setVisible(false);
+							secondArg.setVisible(false);
+							thresholdText.setVisible(true);
+							storeThreshold.clear();
+							storeThreshold
+									.addAll(ThresholdStore.thresholdsSimilarity);
+							storeThreshold.commitChanges();
+							comboThreshold.clear();
+							comboThreshold.reset();
+							comboThreshold.setVisible(true);
+							comboThreshold.setValue(ThresholdStore
+									.defaultThresholdSimilarity());
+
 						}
 						btnAdd.setVisible(true);
 						btnDel.setVisible(true);
@@ -266,10 +360,14 @@ public class ConditionWidget extends SimpleContainer {
 							firstArgDate.setVisible(false);
 							andText.setVisible(false);
 							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						} else {
 							firstArg.setVisible(false);
 							andText.setVisible(false);
 							secondArg.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						}
 						btnAdd.setVisible(true);
 						btnDel.setVisible(true);
@@ -296,10 +394,14 @@ public class ConditionWidget extends SimpleContainer {
 			horiz.add(firstArgDate, new BoxLayoutData(new Margins(0)));
 			horiz.add(andText, new BoxLayoutData(new Margins(0)));
 			horiz.add(secondArgDate, new BoxLayoutData(new Margins(0)));
+			horiz.add(thresholdText, new BoxLayoutData(new Margins(0)));
+			horiz.add(comboThreshold, new BoxLayoutData(new Margins(0)));
 		} else {
 			horiz.add(firstArg, new BoxLayoutData(new Margins(0)));
 			horiz.add(andText, new BoxLayoutData(new Margins(0)));
 			horiz.add(secondArg, new BoxLayoutData(new Margins(0)));
+			horiz.add(thresholdText, new BoxLayoutData(new Margins(0)));
+			horiz.add(comboThreshold, new BoxLayoutData(new Margins(0)));
 		}
 		horiz.add(btnAdd, new BoxLayoutData(new Margins(2, 0, 2, 0)));
 		horiz.add(btnDel, new BoxLayoutData(new Margins(2, 0, 2, 0)));
@@ -340,6 +442,35 @@ public class ConditionWidget extends SimpleContainer {
 		secondArgDate.setItemId(itemIdSecondArgDate);
 		secondArgDate.setVisible(false);
 
+		// Combo Similarity and Levenshtein threshold
+		ThresholdProperties propsThreshold = GWT
+				.create(ThresholdProperties.class);
+		Log.debug("Props: " + propsThreshold);
+		final ListStore<Threshold> storeThreshold = new ListStore<Threshold>(
+				propsThreshold.id());
+		Log.debug("StoreThreshold: " + storeThreshold);
+		storeThreshold.addAll(ThresholdStore.thresholdsLevenshtein);
+
+		Log.debug("StoreThreshold created");
+		final ComboBox<Threshold> comboThreshold = new ComboBox<Threshold>(
+				storeThreshold, propsThreshold.label());
+
+		Log.debug("Combo Threshold created");
+
+		comboThreshold.setEmptyText("Select a threshold...");
+		comboThreshold.setItemId(itemIdComboThreshold);
+		comboThreshold.setWidth("100px");
+		comboThreshold.setEditable(false);
+		comboThreshold.setTriggerAction(TriggerAction.ALL);
+		comboThreshold.setVisible(false);
+		
+
+		final HTML thresholdText = new HTML(
+				"<div style='vertical-align:middle; margin-left:2px;margin-right:2px;margin-top:4px;'>Threshold:</div>");
+		thresholdText.setVisible(false);
+
+		
+		// Button
 		final IconButton btnAdd = new IconButton();
 		btnAdd.setItemId(itemIdBtnAdd);
 		btnAdd.setIcon(ExpressionResources.INSTANCE.add());
@@ -415,15 +546,19 @@ public class ConditionWidget extends SimpleContainer {
 					case NOT_MATCH_REGEX:
 					case IN:
 					case NOT_IN:
-					case SOUNDEX:	
+					case SOUNDEX:
 						if (column.getDataTypeName().compareTo("Date") == 0) {
 							firstArgDate.setVisible(true);
 							andText.setVisible(false);
 							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						} else {
 							firstArg.setVisible(true);
 							andText.setVisible(false);
 							secondArg.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						}
 						btnAdd.setVisible(true);
 						btnDel.setVisible(true);
@@ -434,24 +569,84 @@ public class ConditionWidget extends SimpleContainer {
 							firstArgDate.setVisible(false);
 							andText.setVisible(false);
 							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						} else {
 							firstArg.setVisible(true);
 							andText.setVisible(true);
 							secondArg.setVisible(true);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						}
 						btnAdd.setVisible(true);
 						btnDel.setVisible(true);
 						break;
+					case LEVENSHTEIN:
+						if (column.getDataTypeName().compareTo("Date") == 0) {
+							firstArgDate.setVisible(false);
+							andText.setVisible(false);
+							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
+						} else {
+							firstArg.setVisible(true);
+							andText.setVisible(false);
+							secondArg.setVisible(false);
+							thresholdText.setVisible(true);
+							storeThreshold.clear();
+							storeThreshold
+									.addAll(ThresholdStore.thresholdsLevenshtein);
+							storeThreshold.commitChanges();
+							comboThreshold.clear();
+							comboThreshold.reset();
+							comboThreshold.setVisible(true);
+							comboThreshold.setValue(ThresholdStore
+									.defaultThresholdLevenshtein());
+
+						}
+						btnAdd.setVisible(true);
+						btnDel.setVisible(true);
+						break;
+					case SIMILARITY:
+						if (column.getDataTypeName().compareTo("Date") == 0) {
+							firstArgDate.setVisible(false);
+							andText.setVisible(false);
+							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
+						} else {
+							firstArg.setVisible(true);
+							andText.setVisible(false);
+							secondArg.setVisible(false);
+							thresholdText.setVisible(true);
+							storeThreshold.clear();
+							storeThreshold
+									.addAll(ThresholdStore.thresholdsSimilarity);
+							storeThreshold.commitChanges();
+							comboThreshold.clear();
+							comboThreshold.reset();
+							comboThreshold.setVisible(true);
+							comboThreshold.setValue(ThresholdStore
+									.defaultThresholdSimilarity());
+
+						}
+						btnAdd.setVisible(true);
+						btnDel.setVisible(true);
+						break;	
 					case IS_NULL:
 					case IS_NOT_NULL:
 						if (column.getDataTypeName().compareTo("Date") == 0) {
 							firstArgDate.setVisible(false);
 							andText.setVisible(false);
 							secondArgDate.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						} else {
 							firstArg.setVisible(false);
 							andText.setVisible(false);
 							secondArg.setVisible(false);
+							thresholdText.setVisible(false);
+							comboThreshold.setVisible(false);
 						}
 						btnAdd.setVisible(true);
 						btnDel.setVisible(true);
@@ -478,10 +673,14 @@ public class ConditionWidget extends SimpleContainer {
 			horiz.add(firstArgDate, new BoxLayoutData(new Margins(0)));
 			horiz.add(andText, new BoxLayoutData(new Margins(0)));
 			horiz.add(secondArgDate, new BoxLayoutData(new Margins(0)));
+			horiz.add(thresholdText, new BoxLayoutData(new Margins(0)));
+			horiz.add(comboThreshold, new BoxLayoutData(new Margins(0)));
 		} else {
 			horiz.add(firstArg, new BoxLayoutData(new Margins(0)));
 			horiz.add(andText, new BoxLayoutData(new Margins(0)));
 			horiz.add(secondArg, new BoxLayoutData(new Margins(0)));
+			horiz.add(thresholdText, new BoxLayoutData(new Margins(0)));
+			horiz.add(comboThreshold, new BoxLayoutData(new Margins(0)));
 		}
 		horiz.add(btnAdd, new BoxLayoutData(new Margins(2, 0, 2, 0)));
 		horiz.add(btnDel, new BoxLayoutData(new Margins(2, 0, 2, 0)));
@@ -490,6 +689,8 @@ public class ConditionWidget extends SimpleContainer {
 
 	}
 
+	
+	@SuppressWarnings("unchecked")
 	public C_Expression getExpression() throws ConditionTypeMapException {
 		C_Expression exp = null;
 		readableExpression = new String();
@@ -499,6 +700,8 @@ public class ConditionWidget extends SimpleContainer {
 		TextField secondArg;
 		DateField firstArgDate;
 		DateField secondArgDate;
+		ComboBox<Threshold> comboThreshold;
+		
 		C_Expression expression;
 
 		DateTimeFormat sdf = DateTimeFormat.getFormat("yyyy-MM-dd");
@@ -508,7 +711,6 @@ public class ConditionWidget extends SimpleContainer {
 		HBoxLayoutContainer horiz;
 		while (iteratorVert.hasNext()) {
 			horiz = (HBoxLayoutContainer) iteratorVert.next();
-			@SuppressWarnings("unchecked")
 			ComboBox<Operation> comboOp = (ComboBox<Operation>) horiz
 					.getItemByItemId(itemIdCombo);
 			Log.debug("combo: " + comboOp.getCurrentValue().toString());
@@ -527,18 +729,22 @@ public class ConditionWidget extends SimpleContainer {
 				expression = mapOp.map(column, comboOp.getCurrentValue()
 						.getOperatorType(),
 						firstDate == null ? null : sdf.format(firstDate),
-						secondDate == null ? null : sdf.format(secondDate));
+						secondDate == null ? null : sdf.format(secondDate)
+						,null);
 			} else {
 
 				firstArg = (TextField) horiz.getItemByItemId(itemIdFirstArg);
 				secondArg = (TextField) horiz.getItemByItemId(itemIdSecondArg);
+				comboThreshold =(ComboBox<Threshold>) horiz.getItemByItemId(itemIdComboThreshold);
+				
 				Log.debug("argLeft: " + firstArg.getCurrentValue()
 						+ " argRight: " + secondArg.getCurrentValue());
 
 				expression = mapOp.map(column, comboOp.getCurrentValue()
 						.getOperatorType(),
 						firstArg == null ? null : firstArg.getCurrentValue(),
-						secondArg == null ? null : secondArg.getCurrentValue());
+						secondArg == null ? null : secondArg.getCurrentValue(),
+						comboThreshold.getCurrentValue()==null?null:comboThreshold.getCurrentValue());
 			}
 			readableExpressionList.add(mapOp.getReadableExpression());
 			Log.debug(expression.toString());
diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/operation/OperationsStore.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/operation/OperationsStore.java
index 7079a52..18c1306 100644
--- a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/operation/OperationsStore.java
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/operation/OperationsStore.java
@@ -55,6 +55,8 @@ public class OperationsStore {
 	    add(new Operation(15,"IN","The value is in",C_OperatorType.IN));   
 	    add(new Operation(16,"NOT_IN","The value is not in",C_OperatorType.NOT_IN)); 
 	    add(new Operation(17,"SOUNDEX","The soundex is equal to", C_OperatorType.SOUNDEX));
+	    add(new Operation(18,"LEVENSHTEIN","Levenshtein", C_OperatorType.LEVENSHTEIN));
+	    add(new Operation(19,"SIMILARITY","Similarity", C_OperatorType.SIMILARITY));
 	}};
 	
 	protected ArrayList<Operation> operationsBoolean = new ArrayList<Operation>() {
diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/Threshold.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/Threshold.java
new file mode 100644
index 0000000..ea04521
--- /dev/null
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/Threshold.java
@@ -0,0 +1,71 @@
+package org.gcube.portlets.user.td.expressionwidget.client.threshold;
+
+import java.io.Serializable;
+
+
+
+/**
+ * 
+ * @author "Giancarlo Panichi" 
+ * <a href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a> 
+ *
+ */
+public class Threshold implements Serializable {
+	
+	private static final long serialVersionUID = 3713817747863556150L;
+	
+	private Integer id;
+	private Float value;
+	private String label;
+	
+	
+	public Threshold(Integer id,Integer value,String label){
+		this.id=id;
+		this.value=new Float(value);
+		this.label=label;
+	}
+
+	public Threshold(Integer id,Float value, String label){
+		this.id=id;
+		this.value=value;
+		this.label=label;
+	}
+
+	
+	public Integer getId() {
+		return id;
+	}
+
+	public void setId(Integer id) {
+		this.id = id;
+	}
+
+	public Float getValue() {
+		return value;
+	}
+
+	public Integer getIntegerValue() {
+		return value.intValue();
+	}
+	
+	public void setValue(Float value) {
+		this.value = value;
+	}
+	
+	
+	
+	public String getLabel() {
+		return label;
+	}
+
+	public void setLabel(String label) {
+		this.label = label;
+	}
+
+	@Override
+	public String toString() {
+		return "Threshold [id=" + id + ", value=" + value + ", label=" + label
+				+ "]";
+	}
+	
+}
diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/ThresholdProperties.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/ThresholdProperties.java
new file mode 100644
index 0000000..b4df22c
--- /dev/null
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/ThresholdProperties.java
@@ -0,0 +1,21 @@
+package org.gcube.portlets.user.td.expressionwidget.client.threshold;
+
+import com.google.gwt.editor.client.Editor.Path;
+import com.sencha.gxt.data.shared.LabelProvider;
+import com.sencha.gxt.data.shared.ModelKeyProvider;
+import com.sencha.gxt.data.shared.PropertyAccess;
+
+/**
+ * 
+ * @author "Giancarlo Panichi" 
+ * <a href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a> 
+ *
+ */
+public interface ThresholdProperties extends PropertyAccess<Threshold> {
+
+	@Path("id")
+	ModelKeyProvider<Threshold> id();
+
+	LabelProvider<Threshold> label();
+
+}
diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/ThresholdStore.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/ThresholdStore.java
new file mode 100644
index 0000000..83d561d
--- /dev/null
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/client/threshold/ThresholdStore.java
@@ -0,0 +1,56 @@
+package org.gcube.portlets.user.td.expressionwidget.client.threshold;
+
+import java.util.ArrayList;
+
+
+
+/**
+ * 
+ * @author "Giancarlo Panichi" 
+ * <a href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a> 
+ *
+ */
+public class ThresholdStore {
+	
+	
+	public static ArrayList<Threshold> thresholdsLevenshtein = new ArrayList<Threshold>() {
+		private static final long serialVersionUID = -6559885743626876431L;
+	{
+	    add(new Threshold(1,1,"1"));
+	    add(new Threshold(2,2,"2"));
+	    add(new Threshold(3,3,"3"));
+	    add(new Threshold(4,4,"4"));
+	    add(new Threshold(5,5,"5"));
+	    add(new Threshold(6,6,"6"));
+	    add(new Threshold(7,7,"7"));
+	    add(new Threshold(8,8,"8"));
+	    add(new Threshold(9,9,"9"));
+	    add(new Threshold(10,10,"10"));
+	}};
+	
+	public static Threshold defaultThresholdLevenshtein(){
+		return new Threshold(2,2,"2");
+	}
+	
+	
+	public static ArrayList<Threshold> thresholdsSimilarity = new ArrayList<Threshold>() {
+		private static final long serialVersionUID = -6559885743626876431L;
+	{
+		 add(new Threshold(1,0.0f,"0"));
+		    add(new Threshold(2,0.1f,"0.1"));
+		    add(new Threshold(3,0.2f,"0.2"));
+		    add(new Threshold(4,0.3f,"0.3"));
+		    add(new Threshold(5,0.4f,"0.4"));
+		    add(new Threshold(6,0.5f,"0.5"));
+		    add(new Threshold(7,0.6f,"0.6"));
+		    add(new Threshold(8,0.7f,"0.7"));
+		    add(new Threshold(9,0.8f,"0.8"));
+		    add(new Threshold(10,0.9f,"0.9"));
+	}};
+	
+	public static Threshold defaultThresholdSimilarity(){
+		return new Threshold(9,0.8f,"0.8");
+	}
+	
+	
+}
diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/C_ExpressionParser.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/C_ExpressionParser.java
index 645d5df..220d6b9 100644
--- a/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/C_ExpressionParser.java
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/server/C_ExpressionParser.java
@@ -28,8 +28,10 @@ import org.gcube.data.analysis.tabulardata.expression.composite.comparable.NotEq
 import org.gcube.data.analysis.tabulardata.expression.composite.comparable.NotGreater;
 import org.gcube.data.analysis.tabulardata.expression.composite.comparable.NotLess;
 import org.gcube.data.analysis.tabulardata.expression.composite.text.Concat;
+import org.gcube.data.analysis.tabulardata.expression.composite.text.Levenshtein;
 import org.gcube.data.analysis.tabulardata.expression.composite.text.Lower;
 import org.gcube.data.analysis.tabulardata.expression.composite.text.MD5;
+import org.gcube.data.analysis.tabulardata.expression.composite.text.Similarity;
 import org.gcube.data.analysis.tabulardata.expression.composite.text.Soundex;
 import org.gcube.data.analysis.tabulardata.expression.composite.text.SubstringByIndex;
 import org.gcube.data.analysis.tabulardata.expression.composite.text.SubstringByRegex;
@@ -92,8 +94,10 @@ import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.compar
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.comparable.C_NotLess;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.functions.C_Cast;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Concat;
+import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Levenshtein;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Lower;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_MD5;
+import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Similarity;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Soundex;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_SubstringByIndex;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_SubstringByRegex;
@@ -271,7 +275,14 @@ public class C_ExpressionParser {
 			break;
 		case "Soundex":
 			ex = getSoundex(exp);
-		default:
+			break;
+		case "Levenshtein":
+			ex = getLevenshtein(exp);
+			break;
+		case "Similarity":
+			ex = getSimilarity(exp);
+			break;	
+		default:	
 			break;
 		}
 
@@ -661,6 +672,27 @@ public class C_ExpressionParser {
 		return soundex;
 	}
 	
+	protected Expression getLevenshtein(C_Expression exp)
+			throws ExpressionParserException {
+		C_Levenshtein e = (C_Levenshtein) exp;
+		Expression left = parse(e.getLeftArgument());
+		Expression right = parse(e.getRightArgument());
+		
+		Levenshtein levenshtein = new Levenshtein(left,right);
+		return levenshtein;
+	}
+	
+	protected Expression getSimilarity(C_Expression exp)
+			throws ExpressionParserException {
+		C_Similarity e = (C_Similarity) exp;
+		Expression left = parse(e.getLeftArgument());
+		Expression right = parse(e.getRightArgument());
+		
+		Similarity similarity = new Similarity(left,right);
+		return similarity;
+	}
+	
+	
 
 	protected Expression getEquals(C_Expression exp)
 			throws ExpressionParserException {
diff --git a/src/main/java/org/gcube/portlets/user/td/expressionwidget/shared/condition/ConditionTypeMap.java b/src/main/java/org/gcube/portlets/user/td/expressionwidget/shared/condition/ConditionTypeMap.java
index 2a56865..4660057 100644
--- a/src/main/java/org/gcube/portlets/user/td/expressionwidget/shared/condition/ConditionTypeMap.java
+++ b/src/main/java/org/gcube/portlets/user/td/expressionwidget/shared/condition/ConditionTypeMap.java
@@ -3,6 +3,8 @@ package org.gcube.portlets.user.td.expressionwidget.shared.condition;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.gcube.portlets.user.td.expressionwidget.client.threshold.Threshold;
+import org.gcube.portlets.user.td.expressionwidget.client.threshold.ThresholdStore;
 import org.gcube.portlets.user.td.expressionwidget.shared.exception.ConditionTypeMapException;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.C_OperatorType;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.comparable.C_Equals;
@@ -13,6 +15,8 @@ import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.compar
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.comparable.C_NotEquals;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.comparable.C_NotGreater;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.comparable.C_NotLess;
+import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Levenshtein;
+import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Similarity;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_Soundex;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_TextBeginsWith;
 import org.gcube.portlets.user.td.expressionwidget.shared.model.composite.text.C_TextContains;
@@ -51,21 +55,21 @@ public class ConditionTypeMap {
 	}
 
 	public C_Expression map(ColumnData column, C_OperatorType operatorType,
-			String firstArg, String secondArg) throws ConditionTypeMapException {
+			String firstArg, String secondArg, Threshold threshold) throws ConditionTypeMapException {
 		Log.debug("ConditionTypeMap Map");
 		C_Expression exp = null;
 		readableExpression = new String();
 		if (column.getTrId() == null) {
-			exp = mapPlaceHolder(column, operatorType, firstArg, secondArg);
+			exp = mapPlaceHolder(column, operatorType, firstArg, secondArg, threshold);
 		} else {
 			exp = mapTypedColumnReference(column, operatorType, firstArg,
-					secondArg);
+					secondArg, threshold);
 		}
 		return exp;
 	}
 
 	public C_Expression mapPlaceHolder(ColumnData column,
-			C_OperatorType operatorType, String firstArg, String secondArg)
+			C_OperatorType operatorType, String firstArg, String secondArg, Threshold threshold)
 			throws ConditionTypeMapException {
 		Log.debug("ConditionTypeMap Map Place Holder");
 		C_Expression exp = null;
@@ -337,6 +341,37 @@ public class ConditionTypeMap {
 			readableExpression = "Equals(Soundex(" + readablePlaceHolder + "),Soundex("
 					+ firstArg + "))";
 			break;	
+		case LEVENSHTEIN:
+			checkTypeArgument(column, firstArg);
+			C_Levenshtein levenshstein=new C_Levenshtein(placeHolder,new TD_Value(dataType, firstArg));
+			Threshold thresholdLev;
+	
+			if(threshold==null){
+				thresholdLev=ThresholdStore.defaultThresholdLevenshtein();
+			} else {
+				thresholdLev=threshold;
+			}
+			exp= new C_LessOrEquals(levenshstein,new TD_Value(ColumnDataType.Integer,
+					thresholdLev.getIntegerValue().toString()));
+			readableExpression = "LessOrEquals(Levenshtein(" + readablePlaceHolder + ","+firstArg+"),"
+					+ thresholdLev.getIntegerValue().toString() + ")";
+			break;
+		case SIMILARITY:
+			checkTypeArgument(column, firstArg);
+			C_Similarity similarity=new C_Similarity(placeHolder,new TD_Value(dataType, firstArg));
+			Threshold thresholdSim;
+	
+			if(threshold==null){
+				thresholdSim=ThresholdStore.defaultThresholdSimilarity();
+			} else {
+				thresholdSim=threshold;
+			}
+			exp= new C_GreaterOrEquals(similarity,new TD_Value(ColumnDataType.Numeric,
+					thresholdSim.getLabel()));
+			readableExpression = "GreaterOrEquals(Similarity(" + readablePlaceHolder + ","+firstArg+"),"
+					+ thresholdSim.getLabel() + ")";	
+			break;
+			
 		default:
 			break;
 		}
@@ -345,7 +380,7 @@ public class ConditionTypeMap {
 	}
 
 	public C_Expression mapTypedColumnReference(ColumnData column,
-			C_OperatorType operatorType, String firstArg, String secondArg)
+			C_OperatorType operatorType, String firstArg, String secondArg, Threshold threshold)
 			throws ConditionTypeMapException {
 		Log.debug("ConditionTypeMap Map Typed Column Reference");
 		C_Expression exp = null;
@@ -622,7 +657,37 @@ public class ConditionTypeMap {
 			exp = new C_Equals(soundexPlaceHolder, soundexValue);
 			readableExpression = "Equals(Soundex(" + columnReference + "),Soundex("
 					+ firstArg + "))";
-			break;		
+			break;	
+		case LEVENSHTEIN:
+			checkTypeArgument(column, firstArg);
+			C_Levenshtein levenshstein=new C_Levenshtein(columnReference,new TD_Value(dataType, firstArg));
+			Threshold thresholdLev;
+	
+			if(threshold==null){
+				thresholdLev=ThresholdStore.defaultThresholdLevenshtein();
+			} else {
+				thresholdLev=threshold;
+			}
+			exp= new C_LessOrEquals(levenshstein,new TD_Value(ColumnDataType.Integer,
+					thresholdLev.getIntegerValue().toString()));
+			readableExpression = "LessOrEquals(Levenshtein(" + readableColumnReference + ","+firstArg+"),"
+					+ thresholdLev.getIntegerValue().toString() + ")";
+			break;
+		case SIMILARITY:
+			checkTypeArgument(column, firstArg);
+			C_Similarity similarity=new C_Similarity(columnReference,new TD_Value(dataType, firstArg));
+			Threshold thresholdSim;
+	
+			if(threshold==null){
+				thresholdSim=ThresholdStore.defaultThresholdSimilarity();
+			} else {
+				thresholdSim=threshold;
+			}
+			exp= new C_GreaterOrEquals(similarity,new TD_Value(ColumnDataType.Numeric,
+					thresholdSim.getLabel()));
+			readableExpression = "GreaterOrEquals(Similarity(" + readableColumnReference + ","+firstArg+"),"
+					+ thresholdSim.getLabel() + ")";		
+			break;
 		default:
 			break;
 		}