diff --git a/lang/en/question.php b/lang/en/question.php
index b4c28040102..71c3460f916 100644
--- a/lang/en/question.php
+++ b/lang/en/question.php
@@ -235,6 +235,7 @@ $string['questionsrescuedfrom'] = 'Questions saved from context {$a}.';
 $string['questionsrescuedfrominfo'] = 'These questions (some of which may be hidden) were saved when context {$a} was deleted because they are still used by some quizzes or other activities.';
 $string['questiontype'] = 'Question type';
 $string['questionuse'] = 'Use question in this activity';
+$string['questionvariant'] = 'Question variant';
 $string['reviewresponse'] = 'Review response';
 $string['saveflags'] = 'Save the state of the flags';
 $string['selectacategory'] = 'Select a category:';
diff --git a/lib/questionlib.php b/lib/questionlib.php
index 0275ef79cd1..c2cb777f9f1 100644
--- a/lib/questionlib.php
+++ b/lib/questionlib.php
@@ -699,20 +699,28 @@ function question_move_category_to_context($categoryid, $oldcontextid, $newconte
  * @param string $preferredbehaviour the behaviour to use for the preview.
  * @param float $maxmark the maximum to mark the question out of.
  * @param question_display_options $displayoptions the display options to use.
+ * @param int $variant the variant of the question to preview. If null, one will
+ *      be picked randomly.
  * @return string the URL.
  */
-function question_preview_url($questionid, $preferredbehaviour, $maxmark, $displayoptions) {
-    return new moodle_url('/question/preview.php', array(
-            'id'              => $questionid,
-            'behaviour'       => $preferredbehaviour,
-            'maxmark'         => $maxmark,
-            'correctness'     => $displayoptions->correctness,
-            'marks'           => $displayoptions->marks,
-            'markdp'          => $displayoptions->markdp,
-            'feedback'        => (bool) $displayoptions->feedback,
-            'generalfeedback' => (bool) $displayoptions->generalfeedback,
-            'rightanswer'     => (bool) $displayoptions->rightanswer,
-            'history'         => (bool) $displayoptions->history));
+function question_preview_url($questionid, $preferredbehaviour, $maxmark, $displayoptions,
+        $variant = null) {
+    $params = array(
+        'id'              => $questionid,
+        'behaviour'       => $preferredbehaviour,
+        'maxmark'         => $maxmark,
+        'correctness'     => $displayoptions->correctness,
+        'marks'           => $displayoptions->marks,
+        'markdp'          => $displayoptions->markdp,
+        'feedback'        => (bool) $displayoptions->feedback,
+        'generalfeedback' => (bool) $displayoptions->generalfeedback,
+        'rightanswer'     => (bool) $displayoptions->rightanswer,
+        'history'         => (bool) $displayoptions->history
+    );
+    if ($variant) {
+        $params['variant'] = $variant;
+    }
+    return new moodle_url('/question/preview.php', $params);
 }
 
 /**
diff --git a/mod/quiz/startattempt.php b/mod/quiz/startattempt.php
index acf8c5ca36c..2b119de63cf 100644
--- a/mod/quiz/startattempt.php
+++ b/mod/quiz/startattempt.php
@@ -144,8 +144,15 @@ if (!($quiz->attemptonlast && $lastattempt)) {
         $questionsinuse[] = $question->id;
     }
 
-    // Start all the quetsions.
-    $quba->start_all_questions(null, time(), null);
+    // Start all the questions.
+    if ($attempt->preview) {
+        $variantoffset = rand(1, 100);
+    } else {
+        $variantoffset = $attemptnumber;
+    }
+    $quba->start_all_questions(
+            new question_variant_pseudorandom_no_repeats_strategy($variantoffset),
+            time());
 
     // Update attempt layout.
     $newlayout = array();
diff --git a/question/engine/lib.php b/question/engine/lib.php
index d1e1d67a8dc..4dde7f249af 100644
--- a/question/engine/lib.php
+++ b/question/engine/lib.php
@@ -765,7 +765,7 @@ abstract class question_utils {
 /**
  * The interface for strategies for controlling which variant of each question is used.
  *
- * @copyright  2010 The Open University
+ * @copyright  2011 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 interface question_variant_selection_strategy {
@@ -782,7 +782,7 @@ interface question_variant_selection_strategy {
 /**
  * A {@link question_variant_selection_strategy} that is completely random.
  *
- * @copyright  2010 The Open University
+ * @copyright  2011 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class question_variant_random_strategy implements question_variant_selection_strategy {
@@ -790,3 +790,49 @@ class question_variant_random_strategy implements question_variant_selection_str
         return rand(1, $maxvariants);
     }
 }
+
+
+/**
+ * A {@link question_variant_selection_strategy} that is effectively random
+ * for the first attempt, and then after that cycles through the available
+ * variants so that the students will not get a repeated variant until they have
+ * seen them all.
+ *
+ * @copyright  2011 The Open University
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class question_variant_pseudorandom_no_repeats_strategy
+        implements question_variant_selection_strategy {
+
+    /** @var int the number of attempts this users has had, including the curent one. */
+    protected $attemptno;
+
+    /** @var int the user id the attempt belongs to. */
+    protected $userid;
+
+    /**
+     * Constructor.
+     * @param int $attemptno The attempt number.
+     * @param int $userid the user the attempt is for (defaults to $USER->id).
+     */
+    public function __construct($attemptno, $userid = null) {
+        $this->attemptno = $attemptno;
+        if (is_null($userid)) {
+            global $USER;
+            $this->userid = $USER->id;
+        } else {
+            $this->userid = $userid;
+        }
+    }
+
+    public function choose_variant($maxvariants, $seed) {
+        if ($maxvariants == 1) {
+            return 1;
+        }
+
+        $hash = sha1($seed . '|user' . $this->userid);
+        $randint = hexdec(substr($hash, 17, 7));
+
+        return ($randint + $this->attemptno) % $maxvariants + 1;
+    }
+}
diff --git a/question/engine/simpletest/helpers.php b/question/engine/simpletest/helpers.php
index e93410b12ee..ee0dc030243 100644
--- a/question/engine/simpletest/helpers.php
+++ b/question/engine/simpletest/helpers.php
@@ -424,10 +424,10 @@ class qbehaviour_walkthrough_test_base extends UnitTestCase {
     }
 
     protected function start_attempt_at_question($question, $preferredbehaviour,
-            $maxmark = null) {
+            $maxmark = null, $variant = 1) {
         $this->quba->set_preferred_behaviour($preferredbehaviour);
         $this->slot = $this->quba->add_question($question, $maxmark);
-        $this->quba->start_all_questions();
+        $this->quba->start_question($this->slot, $variant);
     }
     protected function process_submission($data) {
         $this->quba->process_action($this->slot, $data);
diff --git a/question/preview.php b/question/preview.php
index 8d0d97b409d..cc84188af39 100644
--- a/question/preview.php
+++ b/question/preview.php
@@ -38,12 +38,14 @@ require_once(dirname(__FILE__) . '/previewlib.php');
 $id = required_param('id', PARAM_INT);
 $question = question_bank::load_question($id);
 require_login();
-$category = $DB->get_record('question_categories', array('id' => $question->category), '*', MUST_EXIST);
+$category = $DB->get_record('question_categories',
+        array('id' => $question->category), '*', MUST_EXIST);
 question_require_capability_on($question, 'use');
 $PAGE->set_pagelayout('popup');
 $PAGE->set_context(get_context_instance_by_id($category->contextid));
 
 // Get and validate display options.
+$maxvariant = $question->get_num_variants();
 $options = new question_preview_options($question);
 $options->load_user_defaults();
 $options->set_from_request();
@@ -57,7 +59,7 @@ if ($previewid) {
     }
     try {
         $quba = question_engine::load_questions_usage_by_activity($previewid);
-    } catch (Exception $e){
+    } catch (Exception $e) {
         print_error('submissionoutofsequencefriendlymessage', 'question',
                 question_preview_url($question->id, $options->behaviour,
                 $options->maxmark, $options), null, $e);
@@ -68,13 +70,21 @@ if ($previewid) {
         print_error('questionidmismatch', 'question');
     }
     $question = $usedquestion;
+    $options->variant = $quba->get_variant($slot);
 
 } else {
     $quba = question_engine::make_questions_usage_by_activity('core_question_preview',
             get_context_instance_by_id($category->contextid));
     $quba->set_preferred_behaviour($options->behaviour);
     $slot = $quba->add_question($question, $options->maxmark);
-    $quba->start_all_questions();
+
+    if ($options->variant) {
+        $options->variant = min($maxvariant, max(1, $options->variant));
+    } else {
+        $options->variant = rand(1, $maxvariant);
+    }
+
+    $quba->start_question($slot, $options->variant);
 
     $transaction = $DB->start_delegated_transaction();
     question_engine::save_questions_usage_by_activity($quba);
@@ -86,7 +96,8 @@ $options->behaviour = $quba->get_preferred_behaviour();
 $options->maxmark = $quba->get_question_max_mark($slot);
 
 // Create the settings form, and initialise the fields.
-$optionsform = new preview_options_form($CFG->wwwroot . '/question/preview.php?id=' . $question->id, $quba);
+$optionsform = new preview_options_form(new moodle_url('/question/preview.php',
+        array('id' => $question->id)), array('quba' => $quba, 'maxvariant' => $maxvariant));
 $optionsform->set_data($options);
 
 // Process change of settings, if that was requested.
@@ -117,7 +128,7 @@ if (data_submitted() && confirm_sesskey()) {
     } else if (optional_param('finish', null, PARAM_BOOL)) {
         try {
             $quba->process_all_actions();
-        } catch (question_out_of_sequence_exception $e){
+        } catch (question_out_of_sequence_exception $e) {
             print_error('submissionoutofsequencefriendlymessage', 'question', $actionurl);
         }
         $quba->finish_all_questions();
@@ -130,7 +141,7 @@ if (data_submitted() && confirm_sesskey()) {
     } else {
         try {
             $quba->process_all_actions();
-        } catch (question_out_of_sequence_exception $e){
+        } catch (question_out_of_sequence_exception $e) {
             print_error('submissionoutofsequencefriendlymessage', 'question', $actionurl);
         }
 
diff --git a/question/previewlib.php b/question/previewlib.php
index 4ae2f7fee41..d3dcdc0330e 100644
--- a/question/previewlib.php
+++ b/question/previewlib.php
@@ -46,14 +46,25 @@ class preview_options_form extends moodleform {
 
         $mform->addElement('header', 'optionsheader', get_string('changeoptions', 'question'));
 
-        $behaviours = question_engine::get_behaviour_options($this->_customdata->get_preferred_behaviour());
-        $mform->addElement('select', 'behaviour', get_string('howquestionsbehave', 'question'), $behaviours);
+        $behaviours = question_engine::get_behaviour_options(
+                $this->_customdata['quba']->get_preferred_behaviour());
+        $mform->addElement('select', 'behaviour',
+                get_string('howquestionsbehave', 'question'), $behaviours);
         $mform->addHelpButton('behaviour', 'howquestionsbehave', 'question');
 
-        $mform->addElement('text', 'maxmark', get_string('markedoutof', 'question'), array('size' => '5'));
+        $mform->addElement('text', 'maxmark', get_string('markedoutof', 'question'),
+                array('size' => '5'));
         $mform->setType('maxmark', PARAM_NUMBER);
 
-        $mform->addElement('select', 'correctness', get_string('whethercorrect', 'question'), $hiddenofvisible);
+        if ($this->_customdata['maxvariant'] > 1) {
+            $variants = range(1, $this->_customdata['maxvariant']);
+            $mform->addElement('select', 'variant', get_string('questionvariant', 'question'),
+                    array_combine($variants, $variants));
+        }
+        $mform->setType('maxmark', PARAM_INT);
+
+        $mform->addElement('select', 'correctness', get_string('whethercorrect', 'question'),
+                $hiddenofvisible);
 
         $marksoptions = array(
             question_display_options::HIDDEN => get_string('notshown', 'question'),
@@ -65,15 +76,20 @@ class preview_options_form extends moodleform {
         $mform->addElement('select', 'markdp', get_string('decimalplacesingrades', 'question'),
                 question_engine::get_dp_options());
 
-        $mform->addElement('select', 'feedback', get_string('specificfeedback', 'question'), $hiddenofvisible);
+        $mform->addElement('select', 'feedback',
+                get_string('specificfeedback', 'question'), $hiddenofvisible);
 
-        $mform->addElement('select', 'generalfeedback', get_string('generalfeedback', 'question'), $hiddenofvisible);
+        $mform->addElement('select', 'generalfeedback',
+                get_string('generalfeedback', 'question'), $hiddenofvisible);
 
-        $mform->addElement('select', 'rightanswer', get_string('rightanswer', 'question'), $hiddenofvisible);
+        $mform->addElement('select', 'rightanswer',
+                get_string('rightanswer', 'question'), $hiddenofvisible);
 
-        $mform->addElement('select', 'history', get_string('responsehistory', 'question'), $hiddenofvisible);
+        $mform->addElement('select', 'history',
+                get_string('responsehistory', 'question'), $hiddenofvisible);
 
-        $mform->addElement('submit', 'submit', get_string('restartwiththeseoptions', 'question'), $hiddenofvisible);
+        $mform->addElement('submit', 'submit',
+                get_string('restartwiththeseoptions', 'question'), $hiddenofvisible);
     }
 }
 
@@ -92,6 +108,9 @@ class question_preview_options extends question_display_options {
     /** @var number the maximum mark to use for this preview. */
     public $maxmark;
 
+    /** @var int the variant of the question to preview. */
+    public $variant;
+
     /** @var string prefix to append to field names to get user_preference names. */
     const OPTIONPREFIX = 'question_preview_options_';
 
@@ -102,6 +121,7 @@ class question_preview_options extends question_display_options {
         global $CFG;
         $this->behaviour = 'deferredfeedback';
         $this->maxmark = $question->defaultmark;
+        $this->variant = null;
         $this->correctness = self::VISIBLE;
         $this->marks = self::MARK_AND_MAX;
         $this->markdp = get_config('quiz', 'decimalpoints');
@@ -129,6 +149,7 @@ class question_preview_options extends question_display_options {
         return array(
             'behaviour' => PARAM_ALPHA,
             'maxmark' => PARAM_NUMBER,
+            'variant' => PARAM_INT,
             'correctness' => PARAM_BOOL,
             'marks' => PARAM_INT,
             'markdp' => PARAM_INT,
@@ -179,7 +200,7 @@ class question_preview_options extends question_display_options {
     public function get_query_string() {
         $querystring = array();
         foreach ($this->get_field_types() as $field => $notused) {
-            if ($field == 'behaviour' || $field == 'maxmark') {
+            if ($field == 'behaviour' || $field == 'maxmark' || is_null($this->$field)) {
                 continue;
             }
             $querystring[] = $field . '=' . $this->$field;
@@ -266,5 +287,6 @@ function restart_preview($previewid, $questionid, $displayoptions) {
         question_engine::delete_questions_usage_by_activity($previewid);
         $transaction->allow_commit();
     }
-    redirect(question_preview_url($questionid, $displayoptions->behaviour, $displayoptions->maxmark, $displayoptions));
+    redirect(question_preview_url($questionid, $displayoptions->behaviour,
+            $displayoptions->maxmark, $displayoptions, $displayoptions->variant));
 }
diff --git a/question/type/calculated/db/simpletest/testupgradelibnewqe.php b/question/type/calculated/db/simpletest/testupgradelibnewqe.php
index da03ef369fc..168283a9074 100644
--- a/question/type/calculated/db/simpletest/testupgradelibnewqe.php
+++ b/question/type/calculated/db/simpletest/testupgradelibnewqe.php
@@ -200,7 +200,7 @@ class qtype_calculated_attempt_upgrader_test extends question_attempt_upgrader_t
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 18,
-            'variant' => 1,
+            'variant' => 10,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -219,7 +219,7 @@ Remember to type a unit.',
                     'fraction' => null,
                     'timecreated' => 1305830650,
                     'userid' => 4,
-                    'data' => array('-_try' => 1, '_dataset' => '10', '_separators' => '.$,',
+                    'data' => array('-_try' => 1, '_separators' => '.$,',
                             '_var_a' => '7.5', '_var_b' => '4.9'),
                 ),
                 1 => (object) array(
@@ -423,7 +423,7 @@ Remember to type a unit.',
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 18,
-            'variant' => 1,
+            'variant' => 11,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -442,7 +442,7 @@ Remember to type a unit.',
                     'fraction' => null,
                     'timecreated' => 1305830661,
                     'userid' => 4,
-                    'data' => array('-_try' => 1, '_dataset' => '11', '_separators' => '.$,',
+                    'data' => array('-_try' => 1, '_separators' => '.$,',
                             '_var_a' => '5.1', '_var_b' => '4.5'),
                 ),
                 1 => (object) array(
@@ -672,7 +672,7 @@ Remember to type a unit.',
                     'fraction' => null,
                     'timecreated' => 1305830744,
                     'userid' => 3,
-                    'data' => array('-_try' => 1, '_dataset' => '1', '_separators' => '.$,',
+                    'data' => array('-_try' => 1, '_separators' => '.$,',
                             '_var_a' => '9.9', '_var_b' => '2.5'),
                 ),
                 1 => (object) array(
diff --git a/question/type/calculated/db/upgradelib.php b/question/type/calculated/db/upgradelib.php
index 91f0fb9aa8b..36fe3712727 100644
--- a/question/type/calculated/db/upgradelib.php
+++ b/question/type/calculated/db/upgradelib.php
@@ -141,7 +141,6 @@ class qtype_calculated_qe2_attempt_updater extends question_qtype_attempt_update
                 $this->replace_expressions_in_text($this->question->questiontext));
         $this->updater->qa->rightanswer = $this->right_answer($this->question);
 
-        $data['_dataset'] = $this->selecteditem;
         foreach ($this->values as $name => $value) {
             $data['_var_' . $name] = $value;
         }
@@ -181,6 +180,7 @@ class qtype_calculated_qe2_attempt_updater extends question_qtype_attempt_update
 
     public function load_dataset($selecteditem) {
         $this->selecteditem = $selecteditem;
+        $this->updater->qa->variant = $selecteditem;
         $this->values = $this->qeupdater->load_dataset(
                 $this->question->id, $selecteditem);
 
diff --git a/question/type/calculated/question.php b/question/type/calculated/question.php
index 5ed0fbe4f75..66f2e9afbd1 100644
--- a/question/type/calculated/question.php
+++ b/question/type/calculated/question.php
@@ -51,7 +51,7 @@ class qtype_calculated_question extends qtype_numerical_question
     public $synchronised;
 
     public function start_attempt(question_attempt_step $step, $variant) {
-        qtype_calculated_question_helper::start_attempt($this, $step);
+        qtype_calculated_question_helper::start_attempt($this, $step, $variant);
         parent::start_attempt($step, $variant);
     }
 
@@ -73,6 +73,19 @@ class qtype_calculated_question extends qtype_numerical_question
                         $ans->correctanswerlength, $ans->correctanswerformat);
         }
     }
+
+    public function get_num_variants() {
+        return $this->datasetloader->get_number_of_items();
+    }
+
+    public function get_variants_selection_seed() {
+        if (!empty($this->synchronised) &&
+                $this->datasetloader->datasets_are_synchronised($question->category)) {
+            return 'category' . $this->category;
+        } else {
+            return parent::get_variants_selection_seed();
+        }
+    }
 }
 
 
@@ -110,24 +123,14 @@ interface qtype_calculated_question_with_expressions {
  */
 abstract class qtype_calculated_question_helper {
     public static function start_attempt(
-            qtype_calculated_question_with_expressions $question, question_attempt_step $step) {
-
-        $maxnumber = $question->datasetloader->get_number_of_items();
-
-        if (!empty($question->synchronised) &&
-                $question->datasetloader->datasets_are_synchronised($question->category)) {
-
-            $setnumber = ($step->get_timecreated() % $maxnumber) + 1;
-        } else {
-            $setnumber = rand(1, $maxnumber);
-        }
+            qtype_calculated_question_with_expressions $question,
+            question_attempt_step $step, $variant) {
 
         $question->vs = new qtype_calculated_variable_substituter(
-                $question->datasetloader->get_values($setnumber),
+                $question->datasetloader->get_values($variant),
                 get_string('decsep', 'langconfig'));
         $question->calculate_all_expressions();
 
-        $step->set_qt_var('_dataset', $setnumber);
         foreach ($question->vs->get_values() as $name => $value) {
             $step->set_qt_var('_var_' . $name, $value);
         }
diff --git a/question/type/calculated/simpletest/testwalkthrough.php b/question/type/calculated/simpletest/testwalkthrough.php
index 008d9e5d00c..5640a6bf558 100644
--- a/question/type/calculated/simpletest/testwalkthrough.php
+++ b/question/type/calculated/simpletest/testwalkthrough.php
@@ -44,8 +44,9 @@ class qtype_calculated_walkthrough_test extends qbehaviour_walkthrough_test_base
             new question_hint(1, 'This is the first hint.', FORMAT_HTML),
             new question_hint(2, 'This is the second hint.', FORMAT_HTML),
         );
-        $this->start_attempt_at_question($q, 'interactive', 3);
+        $this->start_attempt_at_question($q, 'interactive', 3, 1);
         $values = $q->vs->get_values();
+        $this->assertEqual($values, $q->datasetloader->load_values(1));
 
         // Check the initial state.
         $this->check_current_state(question_state::$todo);
diff --git a/question/type/calculatedmulti/db/simpletest/testupgradelibnewqe.php b/question/type/calculatedmulti/db/simpletest/testupgradelibnewqe.php
index ade8c716811..28668a6c01e 100644
--- a/question/type/calculatedmulti/db/simpletest/testupgradelibnewqe.php
+++ b/question/type/calculatedmulti/db/simpletest/testupgradelibnewqe.php
@@ -227,7 +227,7 @@ class qtype_calculatedmulti_attempt_upgrader_test extends question_attempt_upgra
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 17,
-            'variant' => 1,
+            'variant' => 3,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -242,7 +242,7 @@ class qtype_calculatedmulti_attempt_upgrader_test extends question_attempt_upgra
                     'fraction' => null,
                     'timecreated' => 1305830650,
                     'userid' => 4,
-                    'data' => array('-_try' => 1, '_dataset' => '3',
+                    'data' => array('-_try' => 1,
                             '_order' => '24,26,27,25', '_var_a' => '4.3', '_var_b' => '5.4'),
                 ),
                 1 => (object) array(
@@ -461,7 +461,7 @@ class qtype_calculatedmulti_attempt_upgrader_test extends question_attempt_upgra
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 17,
-            'variant' => 1,
+            'variant' => 8,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -476,7 +476,7 @@ class qtype_calculatedmulti_attempt_upgrader_test extends question_attempt_upgra
                     'fraction' => null,
                     'timecreated' => 1305830661,
                     'userid' => 4,
-                    'data' => array('-_try' => 1, '_dataset' => '8',
+                    'data' => array('-_try' => 1,
                             '_order' => '25,24,27,26', '_var_a' => '3.7', '_var_b' => '6.0'),
                 ),
                 1 => (object) array(
@@ -739,7 +739,7 @@ class qtype_calculatedmulti_attempt_upgrader_test extends question_attempt_upgra
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 17,
-            'variant' => 1,
+            'variant' => 7,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -754,7 +754,7 @@ class qtype_calculatedmulti_attempt_upgrader_test extends question_attempt_upgra
                     'fraction' => null,
                     'timecreated' => 1305830744,
                     'userid' => 3,
-                    'data' => array('-_try' => 1, '_dataset' => '7',
+                    'data' => array('-_try' => 1,
                             '_order' => '26,24,25,27', '_var_a' => '4.4', '_var_b' => '8.2'),
                 ),
                 1 => (object) array(
diff --git a/question/type/calculatedmulti/db/upgradelib.php b/question/type/calculatedmulti/db/upgradelib.php
index 31db43dbad4..5bd757968ef 100644
--- a/question/type/calculatedmulti/db/upgradelib.php
+++ b/question/type/calculatedmulti/db/upgradelib.php
@@ -164,7 +164,6 @@ class qtype_calculatedmulti_qe2_attempt_updater extends question_qtype_attempt_u
                 $this->replace_expressions_in_text($this->question->questiontext));
         $this->updater->qa->rightanswer = $this->right_answer($this->question);
 
-        $data['_dataset'] = $this->selecteditem;
         foreach ($this->values as $name => $value) {
             $data['_var_' . $name] = $value;
         }
@@ -205,6 +204,7 @@ class qtype_calculatedmulti_qe2_attempt_updater extends question_qtype_attempt_u
 
     public function load_dataset($selecteditem) {
         $this->selecteditem = $selecteditem;
+        $this->updater->qa->variant = $selecteditem;
         $this->values = $this->qeupdater->load_dataset(
                 $this->question->id, $selecteditem);
 
diff --git a/question/type/calculatedmulti/question.php b/question/type/calculatedmulti/question.php
index 8b497f46b1f..aa96ac2747e 100644
--- a/question/type/calculatedmulti/question.php
+++ b/question/type/calculatedmulti/question.php
@@ -52,8 +52,8 @@ class qtype_calculatedmulti_single_question extends qtype_multichoice_single_que
     public $synchronised;
 
     public function start_attempt(question_attempt_step $step, $variant) {
-        qtype_calculated_question_helper::start_attempt($this, $step);
-        parent::start_attempt($step);
+        qtype_calculated_question_helper::start_attempt($this, $step, $variant);
+        parent::start_attempt($step, $variant);
     }
 
     public function apply_attempt_state(question_attempt_step $step) {
@@ -64,6 +64,20 @@ class qtype_calculatedmulti_single_question extends qtype_multichoice_single_que
     public function calculate_all_expressions() {
         qtype_calculatedmulti_calculate_helper::calculate_all_expressions($this);
     }
+
+
+    public function get_num_variants() {
+        return $this->datasetloader->get_number_of_items();
+    }
+
+    public function get_variants_selection_seed() {
+        if (!empty($this->synchronised) &&
+                $this->datasetloader->datasets_are_synchronised($question->category)) {
+            return 'category' . $this->category;
+        } else {
+            return parent::get_variants_selection_seed();
+        }
+    }
 }
 
 
diff --git a/question/type/calculatedmulti/simpletest/testwalkthrough.php b/question/type/calculatedmulti/simpletest/testwalkthrough.php
index 847021358c6..f0fcc25a0ee 100644
--- a/question/type/calculatedmulti/simpletest/testwalkthrough.php
+++ b/question/type/calculatedmulti/simpletest/testwalkthrough.php
@@ -44,8 +44,9 @@ class qtype_calculatedmulti_walkthrough_test extends qbehaviour_walkthrough_test
             new question_hint(1, 'This is the first hint.', FORMAT_HTML),
             new question_hint(2, 'This is the second hint.', FORMAT_HTML),
         );
-        $this->start_attempt_at_question($q, 'interactive', 3);
+        $this->start_attempt_at_question($q, 'interactive', 3, 2);
         $values = $q->vs->get_values();
+        $this->assertEqual($values, $q->datasetloader->load_values(2));
 
         // Check the initial state.
         $this->check_current_state(question_state::$todo);
diff --git a/question/type/calculatedsimple/db/simpletest/testupgradelibnewqe.php b/question/type/calculatedsimple/db/simpletest/testupgradelibnewqe.php
index 191d8194d5b..7f8b56d59a0 100644
--- a/question/type/calculatedsimple/db/simpletest/testupgradelibnewqe.php
+++ b/question/type/calculatedsimple/db/simpletest/testupgradelibnewqe.php
@@ -191,7 +191,7 @@ class qtype_calculatedsimple_attempt_upgrader_test extends question_attempt_upgr
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 16,
-            'variant' => 1,
+            'variant' => 7,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -206,7 +206,7 @@ class qtype_calculatedsimple_attempt_upgrader_test extends question_attempt_upgr
                     'fraction' => null,
                     'timecreated' => 1305830650,
                     'userid' => 4,
-                    'data' => array('-_try' => 1, '_dataset' => '7', '_separators' => '.$,',
+                    'data' => array('-_try' => 1, '_separators' => '.$,',
                             '_var_a' => '3', '_var_b' => '6'),
                 ),
                 1 => (object) array(
@@ -401,7 +401,7 @@ class qtype_calculatedsimple_attempt_upgrader_test extends question_attempt_upgr
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 16,
-            'variant' => 1,
+            'variant' => 4,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -416,7 +416,7 @@ class qtype_calculatedsimple_attempt_upgrader_test extends question_attempt_upgr
                     'fraction' => null,
                     'timecreated' => 1305830661,
                     'userid' => 4,
-                    'data' => array('-_try' => 1, '_dataset' => '4', '_separators' => '.$,',
+                    'data' => array('-_try' => 1, '_separators' => '.$,',
                             '_var_a' => '6.4', '_var_b' => '9'),
                 ),
                 1 => (object) array(
@@ -603,7 +603,7 @@ class qtype_calculatedsimple_attempt_upgrader_test extends question_attempt_upgr
         $expectedqa = (object) array(
             'behaviour' => 'adaptive',
             'questionid' => 16,
-            'variant' => 1,
+            'variant' => 6,
             'maxmark' => 1.0000000,
             'minfraction' => 0,
             'flagged' => 0,
@@ -618,7 +618,7 @@ class qtype_calculatedsimple_attempt_upgrader_test extends question_attempt_upgr
                     'fraction' => null,
                     'timecreated' => 1305830744,
                     'userid' => 3,
-                    'data' => array('-_try' => 1, '_dataset' => '6', '_separators' => '.$,',
+                    'data' => array('-_try' => 1, '_separators' => '.$,',
                             '_var_a' => '6.1', '_var_b' => '7'),
                 ),
                 1 => (object) array(