Index: /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IEventTaskInstance.java
===================================================================
--- /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IEventTaskInstance.java	(revision 1397)
+++ /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IEventTaskInstance.java	(revision 1398)
@@ -19,5 +19,5 @@
 /**
  * <p>
- * TODO comment
+ * the instance of an {@link IEventTask}. The instance refers to the concrete event it represents.
  * </p>
  * 
Index: /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IIterationInstance.java
===================================================================
--- /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IIterationInstance.java	(revision 1397)
+++ /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IIterationInstance.java	(revision 1398)
@@ -17,5 +17,6 @@
 /**
  * <p>
- * TODO comment
+ * the instance of an {@link IIteration}. The instance may have several children each being an
+ * instance of the task marked by the iteration of which this is an instance.
  * </p>
  * 
Index: /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IOptionalInstance.java
===================================================================
--- /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IOptionalInstance.java	(revision 1397)
+++ /trunk/autoquest-core-tasktrees/src/main/java/de/ugoe/cs/autoquest/tasktrees/treeifc/IOptionalInstance.java	(revision 1398)
@@ -17,5 +17,7 @@
 /**
  * <p>
- * TODO comment
+ * the instance of an {@link IOptional}. The instance may have a child being an
+ * instance of the task marked by the iteration of which this is an instance. If this instance
+ * does not have a child, the optional child task was not executed.
  * </p>
  * 
@@ -26,5 +28,5 @@
     /**
      * <p>
-     * returns the child of the optional
+     * returns the child of the optional of null if the optional was not executed
      * </p>
      *