diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 22476a9..3289a48 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -5,7 +5,6 @@
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/src/main/scala/org/template/textclassification/Preparator.scala" afterPath="$PROJECT_DIR$/src/main/scala/org/template/textclassification/Preparator.scala" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/src/main/scala/org/template/textclassification/PreparedData.scala" afterPath="$PROJECT_DIR$/src/main/scala/org/template/textclassification/PreparedData.scala" />
       <change type="MODIFICATION" beforePath="$PROJECT_DIR$/engine.json" afterPath="$PROJECT_DIR$/engine.json" />
-      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/data/import_eventserver.py" afterPath="$PROJECT_DIR$/data/import_eventserver.py" />
     </list>
     <ignored path="TextManipulationEngine.iws" />
     <ignored path=".idea/workspace.xml" />
@@ -49,11 +48,11 @@
           </provider>
         </entry>
       </file>
-      <file leaf-file-name="PreparedData.scala" pinned="false" current-in-tab="true">
+      <file leaf-file-name="PreparedData.scala" pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/PreparedData.scala">
           <provider selected="true" editor-type-id="text-editor">
-            <state vertical-scroll-proportion="0.80261594">
-              <caret line="65" column="23" selection-start-line="65" selection-start-column="23" selection-end-line="65" selection-end-column="23" />
+            <state vertical-scroll-proportion="0.0">
+              <caret line="67" column="28" selection-start-line="67" selection-start-column="28" selection-end-line="67" selection-end-column="28" />
               <folding />
             </state>
           </provider>
@@ -63,7 +62,7 @@
         <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/Preparator.scala">
           <provider selected="true" editor-type-id="text-editor">
             <state vertical-scroll-proportion="0.0">
-              <caret line="34" column="0" selection-start-line="34" selection-start-column="0" selection-end-line="34" selection-end-column="0" />
+              <caret line="12" column="11" selection-start-line="12" selection-start-column="11" selection-end-line="12" selection-end-column="11" />
               <folding />
             </state>
           </provider>
@@ -113,7 +112,7 @@
         <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/DataSource.scala">
           <provider selected="true" editor-type-id="text-editor">
             <state vertical-scroll-proportion="0.0">
-              <caret line="106" column="11" selection-start-line="106" selection-start-column="11" selection-end-line="106" selection-end-column="11" />
+              <caret line="109" column="18" selection-start-line="109" selection-start-column="18" selection-end-line="109" selection-end-column="18" />
               <folding />
             </state>
           </provider>
@@ -129,11 +128,11 @@
           </provider>
         </entry>
       </file>
-      <file leaf-file-name="engine.json" pinned="false" current-in-tab="false">
+      <file leaf-file-name="engine.json" pinned="false" current-in-tab="true">
         <entry file="file://$PROJECT_DIR$/engine.json">
           <provider selected="true" editor-type-id="text-editor">
-            <state vertical-scroll-proportion="-16.25">
-              <caret line="26" column="1" selection-start-line="26" selection-start-column="1" selection-end-line="26" selection-end-column="1" />
+            <state vertical-scroll-proportion="0.33047736">
+              <caret line="18" column="17" selection-start-line="18" selection-start-column="17" selection-end-line="18" selection-end-column="17" />
               <folding />
             </state>
           </provider>
@@ -159,10 +158,10 @@
         <option value="$PROJECT_DIR$/src/main/scala/org/template/textclassification/Engine.scala" />
         <option value="$PROJECT_DIR$/src/main/scala/org/template/textclassification/DataSource.scala" />
         <option value="$PROJECT_DIR$/src/main/scala/org/template/textclassification/Evaluation.scala" />
-        <option value="$PROJECT_DIR$/engine.json" />
         <option value="$PROJECT_DIR$/data/import_eventserver.py" />
-        <option value="$PROJECT_DIR$/src/main/scala/org/template/textclassification/Preparator.scala" />
         <option value="$PROJECT_DIR$/src/main/scala/org/template/textclassification/PreparedData.scala" />
+        <option value="$PROJECT_DIR$/src/main/scala/org/template/textclassification/Preparator.scala" />
+        <option value="$PROJECT_DIR$/engine.json" />
       </list>
     </option>
   </component>
@@ -918,12 +917,12 @@
       <option name="number" value="Default" />
       <updated>1430951117412</updated>
       <workItem from="1430951119557" duration="5853000" />
-      <workItem from="1430981904623" duration="9414000" />
+      <workItem from="1430981904623" duration="9980000" />
     </task>
     <servers />
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="15267000" />
+    <option name="totallyTimeSpent" value="15833000" />
   </component>
   <component name="ToolWindowManager">
     <frame x="2436" y="22" width="1305" height="938" extended-state="0" />
@@ -1096,14 +1095,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/Engine.scala">
-      <provider selected="true" editor-type-id="text-editor">
-        <state vertical-scroll-proportion="0.0">
-          <caret line="26" column="6" selection-start-line="26" selection-start-column="6" selection-end-line="26" selection-end-column="6" />
-          <folding />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/NBModel.scala">
       <provider selected="true" editor-type-id="text-editor">
         <state vertical-scroll-proportion="0.0">
@@ -1122,18 +1113,10 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/engine.json">
-      <provider selected="true" editor-type-id="text-editor">
-        <state vertical-scroll-proportion="-16.25">
-          <caret line="26" column="1" selection-start-line="26" selection-start-column="1" selection-end-line="26" selection-end-column="1" />
-          <folding />
-        </state>
-      </provider>
-    </entry>
-    <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/DataSource.scala">
+    <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/PreparedData.scala">
       <provider selected="true" editor-type-id="text-editor">
         <state vertical-scroll-proportion="0.0">
-          <caret line="106" column="11" selection-start-line="106" selection-start-column="11" selection-end-line="106" selection-end-column="11" />
+          <caret line="67" column="28" selection-start-line="67" selection-start-column="28" selection-end-line="67" selection-end-column="28" />
           <folding />
         </state>
       </provider>
@@ -1141,15 +1124,31 @@
     <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/Preparator.scala">
       <provider selected="true" editor-type-id="text-editor">
         <state vertical-scroll-proportion="0.0">
-          <caret line="34" column="0" selection-start-line="34" selection-start-column="0" selection-end-line="34" selection-end-column="0" />
+          <caret line="12" column="11" selection-start-line="12" selection-start-column="11" selection-end-line="12" selection-end-column="11" />
           <folding />
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/PreparedData.scala">
+    <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/Engine.scala">
       <provider selected="true" editor-type-id="text-editor">
-        <state vertical-scroll-proportion="0.80261594">
-          <caret line="65" column="23" selection-start-line="65" selection-start-column="23" selection-end-line="65" selection-end-column="23" />
+        <state vertical-scroll-proportion="0.0">
+          <caret line="26" column="6" selection-start-line="26" selection-start-column="6" selection-end-line="26" selection-end-column="6" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/src/main/scala/org/template/textclassification/DataSource.scala">
+      <provider selected="true" editor-type-id="text-editor">
+        <state vertical-scroll-proportion="0.0">
+          <caret line="109" column="18" selection-start-line="109" selection-start-column="18" selection-end-line="109" selection-end-column="18" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/engine.json">
+      <provider selected="true" editor-type-id="text-editor">
+        <state vertical-scroll-proportion="0.33047736">
+          <caret line="18" column="17" selection-start-line="18" selection-start-column="17" selection-end-line="18" selection-end-column="17" />
           <folding />
         </state>
       </provider>
diff --git a/engine.json b/engine.json
index 037aafd..6369cc7 100644
--- a/engine.json
+++ b/engine.json
@@ -12,7 +12,7 @@
     "params": {
       "nMin": 1,
       "nMax": 2,
-      "inverseIdfMin" : 0.1,
+      "inverseIdfMin" : 0,
       "inverseIdfMax" : 0.9
     }
   },
diff --git a/src/main/scala/org/template/textclassification/Preparator.scala b/src/main/scala/org/template/textclassification/Preparator.scala
index 5275f3a..5c9f7f1 100644
--- a/src/main/scala/org/template/textclassification/Preparator.scala
+++ b/src/main/scala/org/template/textclassification/Preparator.scala
@@ -13,7 +13,8 @@
 case class PreparatorParams(
   nMin: Int,
   nMax: Int,
-  cutoff : Double
+  inverseIdfMin : Double,
+  inverseIdfMax : Double
 ) extends Params
 
 
@@ -24,7 +25,7 @@
 
   // Prepare your training data.
   def prepare(sc : SparkContext, td: TrainingData): PreparedData = {
-    new PreparedData(td, pp.nMin, pp.nMax, pp.cutoff)
+    new PreparedData(td, pp.nMin, pp.nMax, pp.inverseIdfMin, pp. inverseIdfMax)
   }
 }
 
diff --git a/src/main/scala/org/template/textclassification/PreparedData.scala b/src/main/scala/org/template/textclassification/PreparedData.scala
index 717c659..04409f6 100644
--- a/src/main/scala/org/template/textclassification/PreparedData.scala
+++ b/src/main/scala/org/template/textclassification/PreparedData.scala
@@ -24,7 +24,8 @@
   val td: TrainingData,
   val nMin: Int,
   val nMax: Int,
-  val cutoff : Double
+  val inverseIdfMin : Double,
+  val inverseIdfMax : Double
 ) extends Serializable {