diff --git a/paddle/gserver/evaluators/Evaluator.cpp b/paddle/gserver/evaluators/Evaluator.cpp
index cde47f572092f5523b406e1a8f44246ba566b8fd..29b5284fe59b5d6e111b33354bb2142078a8fc03 100644
--- a/paddle/gserver/evaluators/Evaluator.cpp
+++ b/paddle/gserver/evaluators/Evaluator.cpp
@@ -102,6 +102,10 @@ public:
   virtual void distributeEval(ParameterClient2* client) {
     mergeResultsOfAllClients(client);
   }
+
+  // Evaluator interface
+protected:
+  std::string getTypeImpl() const { return "classification_error"; }
 };
 
 /**
@@ -140,6 +144,10 @@ public:
   virtual void distributeEval(ParameterClient2* client) {
     mergeResultsOfAllClients(client);
   }
+
+  // Evaluator interface
+protected:
+  std::string getTypeImpl() const { return "seq_classification_error"; }
 };
 REGISTER_EVALUATOR(seq_classification_error,
                    SequenceClassificationErrorEvaluator);
@@ -230,6 +238,10 @@ public:
 private:
   IVectorPtr cpuLabel_;
   MatrixPtr cpuWeight_;
+
+  // Evaluator interface
+protected:
+  std::string getTypeImpl() const { return "sum"; }
 };
 /**
  * @brief column sum Evaluator
@@ -337,10 +349,18 @@ public:
   }
 
 private:
-  ColumnSumEvaluator() {}
   int32_t colIdx_;
   size_t colNum_;
   MatrixPtr sum_; /* cpu matrix */
+
+  // Evaluator interface
+protected:
+  std::string getTypeImpl() const {
+    if (colIdx_ == -1)
+      return "last-column-sum";
+    else
+      return "column-sum";
+  }
 };
 
 void AucEvaluator::start() {
@@ -791,7 +811,6 @@ void PrecisionRecallEvaluator::storeLocalValues() const {
 
 void PrecisionRecallEvaluator::getNames(std::vector<std::string>* names) {
   this->storeLocalValues();
-  names->clear();
   names->reserve(this->values_.size());
   for (auto it = this->values_.begin(); it != this->values_.end(); ++it) {
     names->push_back(this->config_.name() + "." + it->first);
@@ -1080,12 +1099,13 @@ public:
   }
 };
 REGISTER_EVALUATOR(value_printer, ValuePrinter);
+
 /**
  * @brief print gradient of each layer.
  *
  * The config file api is gradient_printer_evaluator.
  */
-class GradientPrinter : public Evaluator {
+class GradientPrinter : public NotGetableEvaluator {
 public:
   virtual void eval(const NeuralNetwork& nn) {
     for (const std::string& name : config_.input_layers()) {
@@ -1108,7 +1128,7 @@ REGISTER_EVALUATOR(gradient_printer, GradientPrinter);
  *
  * The config file api is maxid_printer_evaluator.
  */
-class MaxIdPrinter : public Evaluator {
+class MaxIdPrinter : public NotGetableEvaluator {
 private:
   IVectorPtr maxIds_;
   MatrixPtr maxValues_;
@@ -1150,7 +1170,7 @@ REGISTER_EVALUATOR(max_id_printer, MaxIdPrinter);
  *
  * The config file api is maxframe_printer_evaluator.
  */
-class MaxFramePrinter : public Evaluator {
+class MaxFramePrinter : public NotGetableEvaluator {
 private:
   IVectorPtr maxIds_;
   MatrixPtr maxValues_;
@@ -1237,7 +1257,7 @@ REGISTER_EVALUATOR(max_frame_printer, MaxFramePrinter);
  * The config file api is seqtext_printer_evaluator.
  *
  */
-class SequenceTextPrinter : public Evaluator {
+class SequenceTextPrinter : public NotGetableEvaluator {
 private:
   /// dict_file, which contains a list of tokens
   std::vector<std::string> dict_;
diff --git a/paddle/gserver/evaluators/Evaluator.h b/paddle/gserver/evaluators/Evaluator.h
index bec3d6e66820fa37168e975f053047474b280838..d5b2a63e35e15752e3ba918dde273671b4c3c0d1 100644
--- a/paddle/gserver/evaluators/Evaluator.h
+++ b/paddle/gserver/evaluators/Evaluator.h
@@ -119,7 +119,6 @@ public:
   static ClassRegistrar<Evaluator> registrar_;
 
   virtual void getNames(std::vector<std::string>* names) {
-    names->clear();
     names->push_back(config_.name());
   }
 
@@ -168,6 +167,25 @@ protected:
   double totalScore_;
 };
 
+class NotGetableEvaluator : public Evaluator {
+  // Evaluator interface
+public:
+  void getNames(std::vector<std::string>* names) {}
+
+  real getValue(const std::string& name, Error* err) const {
+    if (err != nullptr) {
+      *err = Error("Not implemented");
+    }
+    return .0f;
+  }
+  std::string getType(const std::string& name, Error* err) const {
+    if (err != nullptr) {
+      *err = Error("Not implemented");
+    }
+    return "";
+  }
+};
+
 class DummyEvaluator : public Evaluator {
 public:
   DummyEvaluator() {}
diff --git a/paddle/gserver/gradientmachines/NeuralNetwork.cpp b/paddle/gserver/gradientmachines/NeuralNetwork.cpp
index 22051e07ee0026bc3c44a8767e265a56b415b8e4..277fb6d8db13ce73e34eb83fef0437470dfb99c1 100644
--- a/paddle/gserver/gradientmachines/NeuralNetwork.cpp
+++ b/paddle/gserver/gradientmachines/NeuralNetwork.cpp
@@ -306,7 +306,6 @@ void NeuralNetwork::onPassEnd() {
 
 class CombinedEvaluator : public Evaluator {
 public:
-  CombinedEvaluator() {}
   void addEvaluator(std::unique_ptr<Evaluator>&& evaluator) {
     evaluators_.emplace_back(std::move(evaluator));
   }
@@ -346,6 +345,50 @@ public:
 
 protected:
   std::vector<std::unique_ptr<Evaluator>> evaluators_;
+
+  // Evaluator interface
+public:
+  void getNames(std::vector<std::string>* names) {
+    for (auto& eval : evaluators_) {
+      eval->getNames(names);
+    }
+  }
+
+  real getValue(const std::string& name, Error* err) const {
+    return this->getMethodHelper<real>(
+        name, err, [&name, err](const std::unique_ptr<Evaluator>& eval) {
+          return eval->getValue(name, err);
+        });
+  }
+  std::string getValueStr(const std::string& name, Error* err) const {
+    return this->getMethodHelper<std::string>(
+        name, err, [&name, err](const std::unique_ptr<Evaluator>& eval) {
+          return eval->getValueStr(name, err);
+        });
+  }
+  std::string getType(const std::string& name, Error* err) const {
+    return this->getMethodHelper<std::string>(
+        name, err, [&name, err](const std::unique_ptr<Evaluator>& eval) {
+          return eval->getType(name, err);
+        });
+  }
+
+private:
+  template <typename T>
+  T getMethodHelper(const std::string& name,
+                    Error* err,
+                    const std::function<T(const std::unique_ptr<Evaluator>&)>&
+                        callback) const {
+    for (auto& eval : evaluators_) {
+      std::vector<std::string> names;
+      eval->getNames(&names);
+      if (std::find(names.begin(), names.end(), name) != names.end()) {
+        return callback(eval);
+      }
+    }
+    if (err != nullptr) *err = Error("No such key %s", name.c_str());
+    return T();
+  }
 };
 
 Evaluator* NeuralNetwork::makeEvaluator() const {