diff --git a/knowledge/survey/browser.py b/knowledge/survey/browser.py
index 657c3e9..30c7cdd 100644
--- a/knowledge/survey/browser.py
+++ b/knowledge/survey/browser.py
@@ -52,9 +52,10 @@ class SurveyView(ConceptView):
                 if key.startswith('question_'):
                     uid = key[len('question_'):]
                     question = adapted(self.getObjectForUid(uid))
-                    value = int(value)
-                    self.data[uid] = value
-                    response.values[question] = value
+                    if value != 'none':
+                        value = int(value)
+                        self.data[uid] = value
+                        response.values[question] = value
             # TODO: store self.data in track
         # else:
         #     get response from track
@@ -65,9 +66,10 @@ class SurveyView(ConceptView):
                         for r in result]
 
     def getValues(self, question):
-        setting = 0
+        setting = None
         if self.data is not None:
-            setting = self.data.get(question.uid) or 0
-        return [dict(value=i, checked=(i == setting)) 
-                    for i in range(question.answerRange)]
+            setting = self.data.get(question.uid)
+        noAnswer = [dict(value='none', checked=(setting == None))]
+        return noAnswer + [dict(value=i, checked=(setting == i)) 
+                                for i in reversed(range(question.answerRange))]
 
diff --git a/knowledge/survey/interfaces.py b/knowledge/survey/interfaces.py
index ea15928..1e23003 100644
--- a/knowledge/survey/interfaces.py
+++ b/knowledge/survey/interfaces.py
@@ -43,11 +43,24 @@ class IQuestionGroup(IConceptSchema, interfaces.IQuestionGroup):
     """ A group of questions within a questionnaire.
     """
 
+    minAnswers = schema.Int(
+        title=_(u'Minimum Number of Answers'),
+        description=_(u'Minumum number of questions that have to be answered. '
+            'Empty means all questions have to be answered.'),
+        default=4,
+        required=False)
+
 
 class IQuestion(IConceptSchema, interfaces.IQuestion):
     """ A single question within a questionnaire.
     """
 
+    required = schema.Bool(
+        title=_(u'Required'),
+        description=_(u'Question must be answered.'),
+        default=False,
+        required=False)
+
     revertAnswerOptions = schema.Bool(
         title=_(u'Negative'),
         description=_(u'Value inversion: High selection means low value.'),
diff --git a/knowledge/survey/view_macros.pt b/knowledge/survey/view_macros.pt
index 3956120..d225219 100644
--- a/knowledge/survey/view_macros.pt
+++ b/knowledge/survey/view_macros.pt
@@ -7,7 +7,7 @@
   <metal:title use-macro="item/conceptMacros/concepttitle" />
   <div tal:condition="feedback">
     <h3 i18n:translate="">Feedback</h3>
-    <table>
+    <table class="listing">
       <tr>
         <th i18n:translate="">Category</th>
         <th i18n:translate="">Response</th>
@@ -23,33 +23,32 @@
   </div>
   <h3 i18n:translate="">Questionnaire</h3>
   <form method="post">
-    <table>
-      <tr>
-        <th></th>
-        <th>
-          <table>
-            <tr>
-              <td i18n:translate="">Does not apply</td>
-              <td style="text-align: right"
-                  i18n:translate="">Fully applies</td>
-            </tr>
-          </table>
-        </th>
-      </tr>
-      <tr tal:repeat="question item/adapted/questions">
-        <td tal:content="question/text" />
-        <td style="white-space: nowrap">
-          <span tal:repeat="value python:item.getValues(question)">&nbsp;
-            <input type="radio"
-                   i18n:attributes="title"         
-                   tal:attributes="
-                        name string:question_${question/uid};
-                        value value/value;
-                        checked value/checked;
-                        title string:survey_value_${value/value}" />&nbsp;
-          </span>
-        </td>
-      </tr>
+    <table class="listing">
+      <tal:qugroup repeat="qugroup item/adapted/questionGroups">
+        <tr>
+          <td><b tal:content="qugroup/title" /></td>
+          <td style="text-align: center"
+              i18n:translate="">No answer</td>
+          <td colspan="2"
+              i18n:translate="">Fully applies</td>
+          <td colspan="2"
+              style="text-align: right"
+              i18n:translate="">Does not apply</td>
+        </tr>
+        <tr tal:repeat="question qugroup/questions">
+          <td tal:content="question/text" />
+          <td style="white-space: nowrap; text-align: center"
+              tal:repeat="value python:item.getValues(question)">
+              <input type="radio"
+                     i18n:attributes="title"         
+                     tal:attributes="
+                          name string:question_${question/uid};
+                          value value/value;
+                          checked value/checked;
+                          title string:survey_value_${value/value}" />&nbsp;
+          </td>
+        </tr>
+      </tal:qugroup>
     </table>
     <br />
     <input type="submit" name="submit" value="Evaluate Questionnaire"
diff --git a/locales/de/LC_MESSAGES/loops.mo b/locales/de/LC_MESSAGES/loops.mo
index 0bf32ea..e8c66bb 100644
Binary files a/locales/de/LC_MESSAGES/loops.mo and b/locales/de/LC_MESSAGES/loops.mo differ
diff --git a/locales/de/LC_MESSAGES/loops.po b/locales/de/LC_MESSAGES/loops.po
index 74f7395..518d611 100644
--- a/locales/de/LC_MESSAGES/loops.po
+++ b/locales/de/LC_MESSAGES/loops.po
@@ -3,7 +3,7 @@ msgstr ""
 
 "Project-Id-Version: 0.13.0\n"
 "POT-Creation-Date: 2007-05-22 12:00 CET\n"
-"PO-Revision-Date: 2013-03-07 12:00 CET\n"
+"PO-Revision-Date: 2013-03-18 12:00 CET\n"
 "Last-Translator: Helmut Merz <helmutm@cy55.de>\n"
 "Language-Team: loops developers <helmutm@cy55.de>\n"
 "MIME-Version: 1.0\n"
@@ -178,8 +178,20 @@ msgstr "Abstufung Bewertungen"
 msgid "Number of items (answer options) to select from."
 msgstr "Anzahl der Abstufungen, aus denen bei der Antwort gewählt werden kann."
 
-msgid "Negativ"
-msgstr "Negativbewertung"
+msgid "Minimum Number of Answers"
+msgstr "Mindestanzahl an Antworten"
+
+msgid "Minumum number of questions that have to be answered. Empty means all questions have to be answered."
+msgstr "Anzahl der Fragen, die mindestens beantwortet werden müssen. Keine Angabe: Es müssen alle Fragen beantwortet werden."
+
+msgid "Required"
+msgstr "Erforderlich"
+
+msgid "Question must be answered."
+msgstr "Frage muss unbedingt beantwortet werden."
+
+msgid "Negative"
+msgstr "Negative Polarität"
 
 msgid "Value inversion: High selection means low value."
 msgstr "Invertierung der Bewertung: Hohe gewählte Stufe bedeutet niedriger Wert."
@@ -196,27 +208,45 @@ msgstr "Kategorie"
 msgid "Response"
 msgstr "Beurteilung"
 
+msgid "No answer"
+msgstr "Keine Antwort"
+
 msgid "Does not apply"
 msgstr "Trifft nicht zu"
 
 msgid "Fully applies"
 msgstr "Trifft voll zu"
 
+msgid "survey_value_none"
+msgstr "Keine Antwort"
+
 msgid "survey_value_0"
-msgstr "trifft für unser Unternehmen überhaupt nicht zu"
+msgstr "Trifft für unser Unternehmen überhaupt nicht zu"
 
 msgid "survey_value_1"
-msgstr "trifft eher nicht zu"
+msgstr "Trifft eher nicht zu"
 
 msgid "survey_value_2"
-msgstr "trifft eher zu"
+msgstr "Trifft eher zu"
 
 msgid "survey_value_3"
-msgstr "trifft für unser Unternehmen voll und ganz zu"
+msgstr "Trifft für unser Unternehmen voll und ganz zu"
 
 msgid "Evaluate Questionnaire"
 msgstr "Fragebogen auswerten"
 
+msgid "Please answer at least $minAnswers questions."
+msgstr "Bitte beantworten Sie mindestens $minAnswers Fragen."
+
+msgid "Please answer all questions."
+msgstr "Bitte beantworten Sie alle Fragen."
+
+msgid "Please answer the obligatory questions marked with an asterisk."
+msgstr "Bitte beantworten Sie die mit einem Stern markierten Pflichtfragen."
+
+msgid "Obligatory question, must be answered"
+msgstr "Pflichtfrage, muss beantwortet werden"
+
 # competence (qualification)
 
 msgid "Validity Period (Months)"