diff --git a/scripts/TestRunner.js b/scripts/TestRunner.js
index 335f04a..4986b00 100644
--- a/scripts/TestRunner.js
+++ b/scripts/TestRunner.js
@@ -93,7 +93,7 @@ rectest.TestRunner = Class( 'TestRunner',
 
         var _self = this,
             run   = this._setFactory.fromId( options.ralgo,
-                test_case, options
+                test_case.getSet( options.set ), options
             );
 
         // allow test case to initialize its display
diff --git a/scripts/set/RandomGroupedSet.js b/scripts/set/RandomGroupedSet.js
index 0db21cc..222f712 100644
--- a/scripts/set/RandomGroupedSet.js
+++ b/scripts/set/RandomGroupedSet.js
@@ -7,12 +7,6 @@ rectest.set.RandomGroupedSet = Class( 'RandomGroupedSet' )
     .implement( rectest.set.Set )
     .extend(
 {
-    /**
-     * Test case being executed
-     * @var {TestCase}
-     */
-    'private _case': null,
-
     /**
      * Number of samples remaining
      * @var {number}
@@ -38,10 +32,9 @@ rectest.set.RandomGroupedSet = Class( 'RandomGroupedSet' )
     'private _setPos': 0,
 
 
-    __construct: function( test_case, options )
+    __construct: function( base_set, options )
     {
-        this._case          = test_case;
-        this._set           = test_case.getSet( options.set );
+        this._set           = base_set;
         this._setLength     = this._set.length;
         this._samplesRemain = +options.samples || -1;
 
diff --git a/scripts/set/Set.js b/scripts/set/Set.js
index 5e7780d..454b168 100644
--- a/scripts/set/Set.js
+++ b/scripts/set/Set.js
@@ -3,7 +3,13 @@
  */
 rectest.set.Set = Interface( 'Set',
 {
-    __construct: [ 'test_case', 'options' ],
+    /**
+     * Create a new set from a base set and the given options
+     *
+     * @param {Array.<string>} base_set base set
+     * @param {Object}         options  configuration options
+     */
+    __construct: [ 'base_set', 'options' ],
 
 
     /**
diff --git a/scripts/set/SetFactory.js b/scripts/set/SetFactory.js
index cf2f9d1..cf382e4 100644
--- a/scripts/set/SetFactory.js
+++ b/scripts/set/SetFactory.js
@@ -3,20 +3,15 @@
  */
 rectest.set.SetFactory = Class( 'SetFactory',
 {
-    'public fromId': function( id, test_case, options )
+    'public fromId': function( id, base_set, options )
     {
         var sets = rectest.set;
 
-        if ( !( Class.isA( rectest.TestCase, test_case ) ) )
-        {
-            throw TypeError( "Invalid test case: " + test_case );
-        }
-
         return [
             null,
             sets.RandomGroupedSet,
             null,
             null
-        ][ id ]( test_case, options );
+        ][ id ]( base_set, options );
     }
 } );