--- loncom/interface/statistics/lonproblemstatistics.pm	2005/08/26 21:53:23	1.105
+++ loncom/interface/statistics/lonproblemstatistics.pm	2006/02/05 19:10:28	1.106
@@ -1,6 +1,6 @@
 # The LearningOnline Network with CAPA
 #
-# $Id: lonproblemstatistics.pm,v 1.105 2005/08/26 21:53:23 albertel Exp $
+# $Id: lonproblemstatistics.pm,v 1.106 2006/02/05 19:10:28 bowersj2 Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1630,7 +1630,7 @@ sub compute_discrimination_factor {
         (\@Resources,
          [&Apache::lonstatistics::get_selected_sections()],
          $Apache::lonstatistics::enrollment_status,undef,
-         $starttime,$endtime);
+         $starttime,$endtime, $symb);
     #
     # compute their percent scores on the problems in the sequence,
     my $number_to_grab = int(scalar(@{$ranking})/4);
@@ -1640,7 +1640,7 @@ sub compute_discrimination_factor {
     my @TopSet    = 
         map { 
             $_->[&Apache::loncoursedata::RNK_student()]; 
-          } @{$ranking}[($num_students-$number_to_grab)..($num_students-1)];
+          } @{$ranking}[-$number_to_grab..0];
     if (! @BottomSet || (@BottomSet == 1 && $BottomSet[0] eq '') ||
         ! @TopSet    || (@TopSet    == 1 && $TopSet[0]    eq '')) {
         return 'nan';