From 664bf34ff68eff85861d99843c61c4280c0f049e Mon Sep 17 00:00:00 2001
From: jamiesensei <jamiesensei>
Date: Mon, 10 Nov 2008 14:42:21 +0000
Subject: [PATCH] MDL-17190 "error in code for calculating discrimination index
 and efficiency for randomly selected questions" Fixed the code for item
 stats.

---
 mod/quiz/report/statistics/qstats.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mod/quiz/report/statistics/qstats.php b/mod/quiz/report/statistics/qstats.php
index 9a260d3673..ef3509d105 100644
--- a/mod/quiz/report/statistics/qstats.php
+++ b/mod/quiz/report/statistics/qstats.php
@@ -79,7 +79,11 @@ class qstats{
 
     function _secondary_states_walker($state, &$stats){
         $gradedifference = ($state->grade - $stats->gradeaverage);
-        $othergradedifference = (($state->sumgrades - $state->grade) - $stats->othergradeaverage);
+        if ($stats->subquestion){
+            $othergradedifference = $state->sumgrades - $stats->othergradeaverage;
+        } else {
+            $othergradedifference = (($state->sumgrades - $state->grade) - $stats->othergradeaverage);
+        }
         $overallgradedifference = $state->sumgrades - $this->sumgradesavg;
         $sortedgradedifference = (array_shift($stats->gradearray) - $stats->gradeaverage);
         $sortedothergradedifference = (array_shift($stats->othergradesarray) - $stats->othergradeaverage);
-- 
2.39.5