diff --git a/src/mpTcptraceData.py b/src/mpTcptraceData.py
index 56a8e18..c2bdaf6 100755
--- a/src/mpTcptraceData.py
+++ b/src/mpTcptraceData.py
@@ -5,6 +5,8 @@ from subprocess import check_output
 import csv
 
 from io import StringIO
+import re
+
 
 
 
@@ -22,7 +24,16 @@ class TcptraceData:
 	def get(self, flow, column):
 		if flow>self.number_of_flows-1:
 			raise Exception("Bad flow index")
-		return self.flows[flow][self.headers.index(column)]
+		value = self.flows[flow][self.headers.index(column)]
+		if re.search("[a-zA-Z]", value):
+			return value
+		elif re.search("\.", value):
+			return float(value)
+		elif re.search("^[0-9]+$", value):
+			return int(value)
+		else:
+			return value
+
 	# returns first packet time of flow
 	def first_packet(self, flow):
 		return float(self.flows[flow][self.header_index("first_packet")])-float(self.flows[0][self.header_index("first_packet")])
diff --git a/src/mpValidations.py b/src/mpValidations.py
index aa53fd7..13cfda6 100644
--- a/src/mpValidations.py
+++ b/src/mpValidations.py
@@ -20,22 +20,27 @@ class Validation:
 # checks a value passed is greater or equal (generic)
 class MinValueValidation(Validation):
 	def validate(self, value):
+		self.value = value
 		return self.compared<=value
 # checks a value passed is greater or equal (generic)
 class MaxValueValidation(Validation):
 	def validate(self, value):
+		self.value = value
 		return self.compared>=value
 # checks a value passed is greater or equal (generic)
 class ExactValueValidation(Validation):
 	def validate(self, value):
+		self.value = value
 		return self.compared==value
 
 # individual flow validation (specific)
 # gets flow_spec = (index, flows) where index is the index of the flow to validate, and flows is the array of flows
 class MinDelayValidation(Validation):
 	def validate(self, flow_spec):
-		(index,trace) = flow_spec
+		(yml,trace) = flow_spec
+		index=yml["index"]
 		val = trace.first_packet(index)-trace.first_packet(0)
+		self.value = val
 		return self.compared<=val
 
 # individual flow validation (specific)
@@ -45,10 +50,19 @@ class MinDelayValidation(Validation):
 #                      - flows is the array of flows
 class MinDelayBetweenValidation(Validation):
 	def validate(self, flow_spec):
-		([index0, index1] ,trace) = flow_spec
+		(yml ,trace) = flow_spec
+		[index0, index1] = yml["index"]
 		val = trace.first_packet(index1)-trace.first_packet(index0)
+		self.value = val
 		return self.compared<=val
 
+class AttributeMinimumDifferenceValidation(Validation):
+	def validate(self, flow_spec):
+		(yml ,trace) = flow_spec
+		[index0, index1] = yml["index"]
+		val = trace.get(index1, yml["attribute"]) - trace.get(index0, yml["attribute"]) 
+		self.value = val
+		return self.compared<=val
 
 
 # Base class testing tcptrace results
@@ -64,21 +78,19 @@ class TcptraceTest:
 	def validate(self):
 		is_ok = True
 		self.logs = ""
-		print self.yml
 		for val in self.yml:
-			print val["name"]
 			tested_value = self.get_tested_value(val) 
 			klass_name=val["name"].title().replace("_","")+"Validation"
 			tester_klass=globals()[klass_name]
 			tester = tester_klass(val)
 			try:
 				if tester.validate(tested_value):
-					self.logs=self.logs+ ("" if self.logs=="" else "\n ")+ "  -" +tester.name()+" OK\n"
+					self.logs=self.logs+ " " + "  OK  :" + val["desc"] +" - " + tester.name()+ " value : " + str(tester.value) +" vs " + str(val["target"]) + "\n"
 				else:
-					self.logs=self.logs+ ("" if self.logs=="" else "\n ")+ "  -" +tester.name()+" FAILS "+ val["desc"] +"\n"
+					self.logs=self.logs+ " " + "  FAIL:" + val["desc"] +" - " + tester.name()+ " value : " + str(tester.value) +" vs " + str(val["target"]) + "\n"
 					is_ok = False
 			except Exception as e:
-				self.logs=self.logs+ ("" if self.logs=="" else "\n ")+ "  -" +tester.name()+" FAILS (EXCEPTION:"+ str(e) + ") "+ val["desc"] +"\n"
+				self.logs=self.logs+ ("" if self.logs=="" else "\n ")+ "  EXCP:" + val["desc"] +" - " + tester.name()+ " " + str(e) + "\n"
 		return is_ok
 	def name(self):
 		return self.__class__.__name__ 
@@ -94,7 +106,7 @@ class NumberOfFlowsTest(TcptraceTest):
 # index can be a compound value, as in the case of min_delay_between where it is an array of indexes
 class FlowsTest(TcptraceTest):
 	def get_tested_value(self, yml):
-		return (yml["index"],self.trace) 
+		return (yml,self.trace) 
 
 
 # Runs tests based on tcptrace
@@ -111,7 +123,7 @@ class TcptraceChecker:
 			klass = globals()[name]
 			r = klass(test, self.trace)
 			if r.validate():
-				self.logs = self.logs + " *" + r.name() + " SUCCESS\n"
+				self.logs = self.logs + " *" + self.test_id + " " + r.name() + " SUCCESS\n"
 				self.logs = self.logs +  r.logs
 			else:
 				self.logs = self.logs + " *" + self.test_id + " " + r.name() + " FAIL\n"
diff --git a/src/tests/base/validation.yml b/src/tests/base/validation.yml
index 6949102..05690c6 100644
--- a/src/tests/base/validation.yml
+++ b/src/tests/base/validation.yml
@@ -8,7 +8,7 @@ tcptrace:
         target: 4
         desc: "Open maximum 4 flows"
       - name: "exact_value"
-        target: 5
+        target: 4
         desc: "Open exactly 4 flows"
   # This tests the flows opened by the connection. See class FlowsTest
   - test: "flows"
@@ -26,3 +26,10 @@ tcptrace:
           - 2
         target: 1
         desc: "Minimum 1 second delay between opening of second and third flow"
+      - name: "attribute_minimum_difference"
+        attribute: "first_packet"
+        index:
+          - 0
+          - 1
+        target: 2
+        desc: "first packet delay 2nd flow"