'. + &mt('Press "Generate Statistics" when you are ready.'). + '
'. + ''. + &mt('It may take some time to update the student data '. + 'for the first analysis. Future analysis this session '. + 'will not have this delay.'). + '
'); + &clean_up(); return; } + $r->rflush(); # - &Gather_Student_Data($r); - # - # - if ($output_mode eq 'html') { - $r->print("". - $ENV{'course.'.$ENV{'request.course.id'}.'.description'}. - "
\n"); - $r->print("".localtime(time)."
"); + # This probably does not need to be done each time we are called, but + # it does not slow things down noticably. + &Apache::loncoursedata::populate_weight_table(); + # + ($navmap,@sequences) = + &Apache::lonstatistics::selected_sequences_with_assessments(); + if (! ref($navmap)) { + $r->print(''.&mt('A course-wide error occurred.').'
'.
+ ''.$navmap.'
'); + &clean_up(); + return; + } + if (exists($env{'form.Excel'})) { + $r->print(''. + &Apache::lonstatistics::section_and_enrollment_description(). + '
'); + &Excel_output($r); + } else { + $r->print(''.' 'x5); $r->rflush(); - if ($show eq 'grouped') { - &output_html_grouped_by_sequence($r); - } elsif ($show eq 'ungrouped') { - &output_html_ungrouped($r); - } - } elsif ($output_mode eq 'excel') { - $r->print("Preparing Excel Spreadsheet
"); - &output_excel($r); - } elsif ($output_mode eq 'plot') { - if ($show eq 'deg of diff') { - &plot_statistics($r,'DoDiff'); - } elsif ($show eq 'per wrong') { - &plot_statistics($r,'%Wrng'); + $r->print(''. + &Apache::lonstatistics::section_and_enrollment_description(). + '
'); + my $count = 0; + foreach my $seq (@sequences) { + my @resources = + &Apache::lonstathelpers::get_resources($navmap,$seq); + $count += scalar(@resources); + } + if ($count > 10) { + $r->print(''. + &mt('Compiling statistics for [_1] problems',$count). + '
'); + if ($count > 30) { + $r->print(''.&mt('This will take some time.').'
'); + } + $r->rflush(); + } + # + my $sortby = $env{'form.sortby'}; + $sortby = 'container' if (! defined($sortby) || $sortby =~ /^\s*$/); + my $plot = $env{'form.plot'}; + if ($plot eq '' || $plot eq 'none') { + undef($plot); + } + if ($sortby eq 'container' && ! defined($plot)) { + &output_sequence_statistics($r); + &output_html_by_sequence($r); + } else { + if (defined($plot)) { + &make_plot($r,$plot); + } + &output_html_stats($r); + &output_sequence_statistics($r); } - } else { - $r->print("Not implemented
"); } + &clean_up(); return; } -############################################### -############################################### +sub output_sequence_statistics { + my ($r) = @_; + my $c=$r->connection(); + $r->print(''.&mt('Sequence Statistics'). + &Apache::loncommon::help_open_topic('Statistics_Sequence'). + '
'); + $r->print(&Apache::loncommon::start_data_table().&Apache::loncommon::start_data_table_header_row()); + $r->print(&sequence_html_header()); + $r->print(&Apache::loncommon::end_data_table_header_row()); + foreach my $seq (@sequences) { + last if ($c->aborted); + &compute_sequence_statistics($seq); + $r->print(&sequence_html_output($seq)); + } + $r->print(&Apache::loncommon::end_data_table()); + $r->rflush(); + return; +} -=pod -=item &output_html_grouped_by_sequence() +########################################################## +########################################################## +## +## HTML output routines +## +########################################################## +########################################################## +sub output_html_by_sequence { + my ($r) = @_; + my $c = $r->connection(); + $r->print(''.&html_preamble()); + # + foreach my $seq (@sequences) { + last if ($c->aborted); + $r->print("
".$seq->compTitle."
". + &Apache::loncommon::start_data_table(). + &Apache::loncommon::start_data_table_header_row(). + &statistics_table_header('no container'). + &Apache::loncommon::end_data_table_header_row()."\n"); + my @Data = &compute_statistics_on_sequence($seq); + foreach my $data (@Data) { + $r->print(&Apache::loncommon::start_data_table_row(). + &statistics_html_table_data($data,'no container'). + &Apache::loncommon::end_data_table_row()."\n"); + } + $r->print(&Apache::loncommon::end_data_table()."\n"); + $r->rflush(); + } + return; +} -Presents the statistics data as an html table organized by the order -the assessments appear in the course. +sub output_html_stats { + my ($r)=@_; + &compute_all_statistics($r); + $r->print(&html_preamble()); + &sort_data($env{'form.sortby'}); + # + my $count=0; + foreach my $data (@StatsArray) { + if ($count++ % 50 == 0) { + $r->print(&Apache::loncommon::end_data_table()); + $r->print(&Apache::loncommon::start_data_table(). + &Apache::loncommon::start_data_table_row(). + &statistics_table_header(). + &Apache::loncommon::end_data_table_row()); + } + $r->print(&Apache::loncommon::start_data_table_row(). + &statistics_html_table_data($data). + &Apache::loncommon::end_data_table_row()); + } + $r->print(&Apache::loncommon::end_data_table_row()); + return; +} + +sub html_preamble { + my $Str=''; + $Str .= "". + $env{'course.'.$env{'request.course.id'}.'.description'}. + "
\n"; + my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits(); + if (defined($starttime) || defined($endtime)) { + # Inform the user what the time limits on the data are. + $Str .= ''.&mt('Statistics on submissions from [_1] to [_2]', + &Apache::lonlocal::locallocaltime($starttime), + &Apache::lonlocal::locallocaltime($endtime) + ).'
'; + } + $Str .= "".&mt('Compiled on [_1]', + &Apache::lonlocal::locallocaltime(time))."
"; + return $Str; +} -=cut ############################################### ############################################### -sub output_html_grouped_by_sequence { - my ($r) = @_; - my $problem_num = 0; - #$r->print(&ProblemStatisticsLegend()); - my @Header = ("Title","Part","#Stdnts","Tries","Mod", - "Mean","#YES","#yes","%Wrng","DoDiff", - "S.D.","Skew.");#,"D.F.1st","D.F.2nd"); - # #FFFFE6 #EEFFCC #DDFFFF FFDDDD #DDFFDD #FFDDFF - foreach my $sequence (&Apache::lonstatistics::Sequences_with_Assess()) { - next if ($sequence->{'num_assess'}<1); - $r->print("".$sequence->{'title'}."
"); - $r->print(''."\n");
- $r->print('
|
'. + &mt('Unable to plot the requested statistic.'). + '
'); + return; + } # - my $sortby = undef; - foreach (@Header) { - if ($ENV{'form.sortby'} eq $_) { - $sortby = $_; + # Build up the data sets to plot + my @Labels; + my @Data; + my $max = 1; + foreach my $data (@StatsArray) { + push(@Labels,$data->{'problem_num'}); + push(@Data,$data->{$datafield}); + if ($data->{$datafield}>$max) { + $max = $data->{$datafield}; } } - if (! defined($sortby) || $sortby eq '') { - $sortby = 'Container'; - } - # If there is more than one sequence, list their titles - my @Sequences = &Apache::lonstatistics::Sequences_with_Assess(); - if (@Sequences > 1) { - unshift(@Header,"Container"); - $show_container = 1; + foreach (1,2,3,4,5,10,15,20,25,40,50,75,100,150,200,250,300,500,600,750, + 1000,1500,2000,2500,3000,3500,4000,5000,7500,10000,15000,20000) { + if ($max <= $_) { + $max = $_; + last; + } } - # - # If the option for showing the problem number is needed, push that - # on the list too - if (defined($option) && $option =~ /show probnum/) { - unshift(@Header,"P#"); + if ($max > 20000) { + $max = 10000*(int($max/10000)+1); } # - $r->print('| '."\n");
- $r->rflush();
- #
- # Compile the data
- my @Statsarray;
- foreach my $sequence (@Sequences) {
- next if ($sequence->{'num_assess'}<1);
- foreach my $resource (@{$sequence->{'contents'}}) {
- next if ($resource->{'type'} ne 'assessment');
- foreach my $part (@{$resource->{'parts'}}) {
- $problem_num++;
- my ($num,$tries,$mod,$mean,$Solved,$solved,$DegOfDiff,$STD,
- $SKEW) = &Apache::loncoursedata::get_problem_statistics
- (undef,$resource->{'symb'},$part,
- $ENV{'request.course.id'});
- #
- $show_part = 1 if ($part ne '0');
- $part = ' ' if ($part == 0);
- #
- my $wrongpercent = 0;
- if (defined($num) && $num > 0) {
- $wrongpercent=int(10*100*($num-$Solved+$solved)/$num)/10;
- }
- push (@Statsarray,
- { 'sequence' => $sequence,
- 'resource' => $resource,
- 'Title' => $resource->{'title'},
- 'Part' => $part,
- '#Stdnts' => $num,
- 'Tries' => $tries,
- 'Mod' => $mod,
- 'Mean' => $mean,
- '#YES' => $Solved,
- '#yes' => $solved,
- '%Wrng' => $wrongpercent,
- 'DoDiff' => $DegOfDiff,
- 'S.D.' => $STD,
- 'Skew' => $SKEW,
- 'problem_num' => $problem_num,
- });
- }
+ $r->print(" ".&Apache::loncommon::DrawBarGraph($title, + 'Problem Number', + $yaxis, + $max, + undef, # colors + \@Labels, + \@Data)." \n"); + return; +} + +sub degrees_plot { + my ($r)=@_; + my $count = scalar(@StatsArray); + my $width = 50 + 10*$count; + $width = 300 if ($width < 300); + my $height = 300; + my $plot = ''; + my $ymax = 0; + my $ymin = 0; + my @Disc; my @Diff; my @Labels; + foreach my $data (@StatsArray) { + push(@Labels,$data->{'problem_num'}); + my $disc = $data->{'deg_of_disc'}; + my $diff = $data->{'deg_of_diff'}; + push(@Disc,$disc); + push(@Diff,$diff); + # + $ymin = $disc if ($ymin > $disc); + $ymin = $diff if ($ymin > $diff); + $ymax = $disc if ($ymax < $disc); + $ymax = $diff if ($ymax < $diff); + } + # + # Make sure we show relevant information. + if ($ymin < 0) { + if (abs($ymin) < 0.05) { + $ymin = 0; + } else { + $ymin = -1; } } - # - # Table Headers - $r->print('
|
'.&Apache::lonxml::xmlparse($r,'web',$plot).'
'.$/; + $r->print($plotresult); return; } +sub plot_dropdown { + my $current = ''; + # + if (defined($env{'form.plot'})) { + $current = $env{'form.plot'}; + } + # + my @Additional_Plots = ( + { graphable=>'yes', + name => 'degrees', + title => 'Difficulty Indexes' }, + { graphable=>'yes', + name => 'tries statistics', + title => 'Tries Statistics' }); + # + my $Str= "\n".''."\n"; + return $Str; +} + ############################################### ############################################### - -=pod - -=item &output_excel() - -Presents the statistical data in an Excel 95 compatable spreadsheet file. - -=cut - +## +## Excel output routines +## ############################################### ############################################### -sub output_excel { +sub Excel_output { my ($r) = @_; - my $filename = '/prtspool/'. - $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'. - time.'_'.rand(1000000000).'.xls'; - # - my $excel_workbook = undef; - my $excel_sheet = undef; - # - my $rows_output = 0; - my $cols_output = 0; - # - # Create sheet - $excel_workbook = Spreadsheet::WriteExcel->new('/home/httpd'.$filename); - # - # Check for errors - if (! defined($excel_workbook)) { - $r->log_error("Error creating excel spreadsheet $filename: $!"); - $r->print("Problems creating new Excel file. ". - "This error has been logged. ". - "Please alert your LON-CAPA administrator"); - return ; - } - # - # The excel spreadsheet stores temporary data in files, then put them - # together. If needed we should be able to disable this (memory only). - # The temporary directory must be specified before calling 'addworksheet'. - # File::Temp is used to determine the temporary directory. - $excel_workbook->set_tempdir($Apache::lonnet::tmpdir); + $r->print(''.&mt('Preparing Excel Spreadsheet').'
'); + ## + ## Compute the statistics + &compute_all_statistics($r); + my $c = $r->connection; + return if ($c->aborted()); + # + my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits(); + ## + ## Create the excel workbook + my ($excel_workbook,$filename,$format) = + &Apache::loncommon::create_workbook($r); + return if (! defined($excel_workbook)); # # Add a worksheet - my $sheetname = $ENV{'course.'.$ENV{'request.course.id'}.'.description'}; + my $sheetname = $env{'course.'.$env{'request.course.id'}.'.description'}; if (length($sheetname) > 31) { $sheetname = substr($sheetname,0,31); } - $excel_sheet = $excel_workbook->addworksheet($sheetname); + my $excel_sheet = $excel_workbook->addworksheet( + &Apache::loncommon::clean_excel_name($sheetname)); + ## + ## Begin creating excel sheet + ## + my ($rows_output,$cols_output) = (0,0); # # Put the course description in the header $excel_sheet->write($rows_output,$cols_output++, - $ENV{'course.'.$ENV{'request.course.id'}.'.description'}); + $env{'course.'.$env{'request.course.id'}.'.description'}, + $format->{'h1'}); $cols_output += 3; # # Put a description of the sections listed my $sectionstring = ''; - my @Sections = @Apache::lonstatistics::SelectedSections; - if (scalar(@Sections) > 1) { - if (scalar(@Sections) > 2) { - my $last = pop(@Sections); - $sectionstring = "Sections ".join(', ',@Sections).', and '.$last; - } else { - $sectionstring = "Sections ".join(' and ',@Sections); - } - } else { - if ($Sections[0] eq 'all') { - $sectionstring = "All sections"; - } else { - $sectionstring = "Section ".$Sections[0]; + $excel_sheet->write($rows_output,$cols_output++, + &Apache::lonstatistics::section_and_enrollment_description('plaintext'), + $format->{'h3'}); + $cols_output += scalar(&Apache::lonstatistics::get_selected_sections()); + $cols_output += scalar(&Apache::lonstatistics::get_selected_groups()); + # + # Time restrictions + my $time_string; + if (defined($starttime)) { + # call localtime but not lonlocal:locallocaltime because excel probably + # cannot handle localized text. Probably. + $time_string .= 'Data collected from '.localtime($time_string); + if (defined($endtime)) { + $time_string .= ' to '.localtime($endtime); } + $time_string .= '.'; + } elsif (defined($endtime)) { + # See note above about lonlocal:locallocaltime + $time_string .= 'Data collected before '.localtime($endtime).'.'; + } + if (defined($time_string)) { + $excel_sheet->write($rows_output,$cols_output++,$time_string); + $cols_output+= 5; } - $excel_sheet->write($rows_output,$cols_output++,$sectionstring); - $cols_output += scalar(@Sections); # # Put the date in there too $excel_sheet->write($rows_output,$cols_output++, 'Compiled on '.localtime(time)); # - $rows_output++; + $rows_output++; $cols_output=0; - # - # Add the headers - my @Header = ("Container","Title","Part","#Stdnts","Tries","Mod", - "Mean","#YES","#yes","%Wrng","DoDiff", - "S.D.","Skew.");#,"D.F.1st","D.F.2nd"); - foreach (@Header) { - $excel_sheet->write($rows_output,$cols_output++,$_); + ## + ## Sequence Statistics + ## + &write_headers($excel_sheet,$format,\$rows_output,\$cols_output, + \@SeqFields); + foreach my $seq (@sequences) { + my $data = $SeqStat{$seq->symb}; + $cols_output=0; + foreach my $field (@SeqFields) { + next if ($field->{'selected'} ne 'yes'); + my $fieldformat = undef; + if (exists($field->{'excel_format'})) { + $fieldformat = $format->{$field->{'excel_format'}}; + } + $excel_sheet->write($rows_output,$cols_output++, + $data->{$field->{'name'}},$fieldformat); + } + $rows_output++; + $cols_output=0; } + ## + ## Resource Statistics + ## $rows_output++; + $cols_output=0; + &write_headers($excel_sheet,$format,\$rows_output,\$cols_output, + \@Fields); # - # Write the data - foreach my $sequence (&Apache::lonstatistics::Sequences_with_Assess()) { - next if ($sequence->{'num_assess'}<1); - foreach my $resource (@{$sequence->{'contents'}}) { - next if ($resource->{'type'} ne 'assessment'); - foreach my $part (@{$resource->{'parts'}}) { - $cols_output=0; - my ($num,$tries,$mod,$mean,$Solved,$solved,$DegOfDiff,$STD, - $SKEW) = &Apache::loncoursedata::get_problem_statistics - (undef,$resource->{'symb'},$part, - $ENV{'request.course.id'}); - # - if (!defined($part) || $part eq '') { - $part = ' '; - } - my $wrongpercent = 0; - if (defined($num) && $num > 0) { - $wrongpercent=int(10*100*($num-$Solved+$solved)/$num)/10; - } - foreach ($sequence->{'title'},$resource->{'title'},$part, - $num,$tries,$mod,$mean,$Solved,$solved,$wrongpercent, - $DegOfDiff,$STD,$SKEW) { - $excel_sheet->write($rows_output,$cols_output++,$_); - } - $rows_output++; + foreach my $data (@StatsArray) { + $cols_output=0; + foreach my $field (@Fields) { + next if ($field->{'selected'} ne 'yes'); + next if ($field->{'name'} eq 'problem_num'); + my $fieldformat = undef; + if (exists($field->{'excel_format'})) { + $fieldformat = $format->{$field->{'excel_format'}}; } + $excel_sheet->write($rows_output,$cols_output++, + $data->{$field->{'name'}},$fieldformat); } + $rows_output++; + $cols_output=0; } # - # Write the excel file $excel_workbook->close(); + # # Tell the user where to get their excel file $r->print(''. - 'Your Excel spreadsheet.'."\n"); + ''. + &mt('Your Excel Spreadsheet').''."\n"); $r->rflush(); return; } -############################################### -############################################### - -=pod - -=item &statistics_html_table_data() - -Help function used to format the rows for HTML table output. - -=cut - -############################################### -############################################### -sub statistics_html_table_data { - my ($resource,$part,$num,$tries,$mod,$mean,$Solved,$solved,$wrongpercent, - $DegOfDiff,$STD,$SKEW,$options) = @_; - my $row = ''; - $row .= '
".&DrawGraph(\@Data,$title,'Problem Number',$yaxis, - $Max)."
\n"); # - # Print out the data - $ENV{'form.sortby'} = 'Contents'; - &output_html_ungrouped($r,'show probnum'); + # Renumber the data set + my $count; + foreach my $data (@StatsArray) { + $data->{'problem_num'} = ++$count; + } return; } +######################################################## +######################################################## + +=pod + +=item &get_statistics() + +Wrapper routine from the call to loncoursedata::get_problem_statistics. +Calls lonstathelpers::get_time_limits() to limit the data set by time +and &compute_discrimination_factor + +Inputs: $sequence, $resource, $part, $problem_num + +Returns: Hash reference with statistics data from +loncoursedata::get_problem_statistics. + +=cut + +######################################################## +######################################################## +sub get_statistics { + my ($sequence,$resource,$part,$problem_num) = @_; + # + my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits(); + my $symb = $resource->symb; + my $courseid = $env{'request.course.id'}; + # + my $data = &Apache::loncoursedata::get_problem_statistics + ([&Apache::lonstatistics::get_selected_sections()], + [&Apache::lonstatistics::get_selected_groups()], + $Apache::lonstatistics::enrollment_status, + $symb,$part,$courseid,$starttime,$endtime); + $data->{'symb'} = $symb; + $data->{'part'} = $part; + $data->{'problem_num'} = $problem_num; + $data->{'container'} = $sequence->compTitle; + $data->{'title'} = $resource->compTitle; + $data->{'title.link'} = $resource->src.'?symb='. + &escape($resource->symb); + # + if ($SelectedFields{'deg_of_disc'}) { + $data->{'deg_of_disc'} = + &compute_discrimination_factor($resource,$part,$sequence); + } + # + # Store in metadata if computations were done for all students + if ($data->{'num_students'} > 1) { + my @Sections = &Apache::lonstatistics::get_selected_sections(); + my $sections = '"'.join(' ',@Sections).'"'; + $sections =~ s/&+/_/g; # Ensure no special characters + $data->{'sections'}=$sections; + $data->{'course'} = $env{'request.course.id'}; + my $urlres=(&Apache::lonnet::decode_symb($resource->symb))[2]; + my %storestats = + &LONCAPA::lonmetadata::dynamic_metadata_storage($data); + my ($dom,$user) = ($urlres=~m{^($LONCAPA::domain_re)/($LONCAPA::username_re)}); + &Apache::lonnet::put('nohist_resevaldata',\%storestats,$dom,$user); + } + # + $data->{'tries_per_correct'} = $data->{'tries'} / + ($data->{'num_solved'}+0.1); + # + # Get the due date for research purposes (commented out most of the time) +# my $duedate = &Apache::lonnet::EXT('resource.'.$part.'.duedate',$symb);; +# my $opendate = &Apache::lonnet::EXT('resource.'.$part.'.opendate',$symb); +# my $maxtries = &Apache::lonnet::EXT('resource.'.$part.'.maxtries',$symb); +# my $hinttries = &Apache::lonnet::EXT('resource.'.$part.'.hinttries',$symb); + my $weight = &Apache::lonnet::EXT('resource.'.$part.'.weight',$symb); + $data->{'weight'} = $weight; +# $data->{'duedate'} = $duedate; +# $data->{'opendate'} = $opendate; +# $data->{'maxtries'} = $maxtries; +# $data->{'hinttries'} = $hinttries; +# $data->{'resptypes'} = join(',',@{$resource->{'partdata'}->{$part}->{'ResponseTypes'}}); + return $data; +} + ############################################### ############################################### -=pod +=pod -=item &DrawGraph() +=item &compute_discrimination_factor() + +Inputs: $Resource, $Sequence + +Returns: integer between -1 and 1 =cut ############################################### ############################################### -sub DrawGraph { - my ($values,$title,$xaxis,$yaxis,$Max)=@_; - $title = '' if (! defined($title)); - $xaxis = '' if (! defined($xaxis)); - $yaxis = '' if (! defined($yaxis)); - # - my $sendValues = join(',', @$values); - my $sendCount = scalar(@$values); - if ( $Max > 1 ) { - if ($Max % 10) { - if ( int($Max) < $Max ) { - $Max++; - $Max = int($Max); - } - } - } else { - $Max = 1; - } - my @GData = ($title,$xaxis,$yaxis,$Max,$sendCount,$sendValues); - return ').')
';
+sub compute_discrimination_factor {
+ my ($resource,$part,$seq) = @_;
+ my $symb = $resource->symb;
+ my @Resources;
+ foreach my $res (&Apache::lonstathelpers::get_resources($navmap,$seq)){
+ next if ($res->symb eq $symb);
+ push (@Resources,$res->symb);
+ }
+ #
+ # rank
+ my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
+ my $ranking =
+ &Apache::loncoursedata::rank_students_by_scores_on_resources
+ (\@Resources,
+ [&Apache::lonstatistics::get_selected_sections()],
+ [&Apache::lonstatistics::get_selected_groups()],
+ $Apache::lonstatistics::enrollment_status,undef,
+ $starttime,$endtime, $symb);
+ #
+ # compute their percent scores on the problems in the sequence,
+ my $number_to_grab = int(scalar(@{$ranking})/4);
+ my $num_students = scalar(@{$ranking});
+ my @BottomSet = map { $_->[&Apache::loncoursedata::RNK_student()];
+ } @{$ranking}[0..$number_to_grab];
+ my @TopSet =
+ map {
+ $_->[&Apache::loncoursedata::RNK_student()];
+ } @{$ranking}[-$number_to_grab..0];
+ if (! @BottomSet || (@BottomSet == 1 && $BottomSet[0] eq '') ||
+ ! @TopSet || (@TopSet == 1 && $TopSet[0] eq '')) {
+ return 'nan';
+ }
+ my ($bottom_sum,$bottom_max) =
+ &Apache::loncoursedata::get_sum_of_scores($symb,$part,\@BottomSet,
+ undef,$starttime,$endtime);
+ my ($top_sum,$top_max) =
+ &Apache::loncoursedata::get_sum_of_scores($symb,$part,\@TopSet,
+ undef,$starttime,$endtime);
+ my $deg_of_disc;
+ if ($top_max == 0 || $bottom_max==0) {
+ $deg_of_disc = 'nan';
+ } else {
+ $deg_of_disc = ($top_sum/$top_max) - ($bottom_sum/$bottom_max);
+ }
+ #&Apache::lonnet::logthis(' '.$top_sum.'/'.$top_max.
+ # ' - '.$bottom_sum.'/'.$bottom_max);
+ return $deg_of_disc;
}
###############################################
###############################################
+##
+## Compute KR-21
+##
+## To compute KR-21, you need the following information:
+##
+## K=the number of items in your test
+## M=the mean score on the test
+## s=the standard deviation of the scores on your test
+##
+## then:
+##
+## KR-21 rk= [K/(K-1)] * [1- (M*(K-M))/(K*s^2))]
+##
+###############################################
+###############################################
+sub compute_sequence_statistics {
+ my ($seq) = @_;
+ my $symb = $seq->symb;
+ my @Resources;
+ my $part_count;
+ foreach my $res (&Apache::lonstathelpers::get_resources($navmap,$seq)) {
+ push (@Resources,$res->symb);
+ $part_count += scalar(@{$res->parts});
+ }
+ my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
+ #
+ # First compute statistics based on student scores
+ my ($smin,$smax,$sMean,$sSTD,$scount,$sMAX) =
+ &Apache::loncoursedata::score_stats
+ ([&Apache::lonstatistics::get_selected_sections()],
+ [&Apache::lonstatistics::get_selected_groups()],
+ $Apache::lonstatistics::enrollment_status,
+ \@Resources,$starttime,$endtime,undef);
+ $SeqStat{$symb}->{'title'} = $seq->compTitle;
+ $SeqStat{$symb}->{'scoremax'} = $smax;
+ $SeqStat{$symb}->{'scoremin'} = $smin;
+ $SeqStat{$symb}->{'scoremean'} = $sMean;
+ $SeqStat{$symb}->{'scorestd'} = $sSTD;
+ $SeqStat{$symb}->{'scorecount'} = $scount;
+ $SeqStat{$symb}->{'max_possible'} = $sMAX;
+ #
+ # Compute statistics based on the number of correct problems
+ # 'correct' is taken to mean
+ my ($cmin,$cmax,$cMean,$cSTD,$ccount)=
+ &Apache::loncoursedata::count_stats
+ ([&Apache::lonstatistics::get_selected_sections()],
+ [&Apache::lonstatistics::get_selected_groups()],
+ $Apache::lonstatistics::enrollment_status,
+ \@Resources,$starttime,$endtime,undef);
+ my $K = $part_count;
+ my $kr_21;
+ if ($K > 1 && $cSTD > 0) {
+ $kr_21 = ($K/($K-1)) * (1 - $cMean*($K-$cMean)/($K*$cSTD**2));
+ } else {
+ $kr_21 = 'nan';
+ }
+ $SeqStat{$symb}->{'countmax'} = $cmax;
+ $SeqStat{$symb}->{'countmin'} = $cmin;
+ $SeqStat{$symb}->{'countstd'} = $cSTD;
+ $SeqStat{$symb}->{'countmean'} = $cMean;
+ $SeqStat{$symb}->{'count'} = $ccount;
+ $SeqStat{$symb}->{'items'} = $K;
+ $SeqStat{$symb}->{'KR-21'}=$kr_21;
+ return;
+}
+
+
=pod
-=item &ProblemStatisticsLegend()
+=item ProblemStatisticsLegend
-=cut
+=over 4
-###############################################
-###############################################
-sub ProblemStatisticsLegend {
- my $Ptr = '';
- $Ptr = '| '; - $Ptr .= '#Stdnts | '; - $Ptr .= 'Total number of students attempted the problem.'; - $Ptr .= ' |
| '; - $Ptr .= 'Tries | '; - $Ptr .= 'Total number of tries for solving the problem.'; - $Ptr .= ' |
| '; - $Ptr .= 'Mod | '; - $Ptr .= 'Largest number of tries for solving the problem by a student.'; - $Ptr .= ' |
| '; - $Ptr .= 'Mean | '; - $Ptr .= 'Average number of tries. [ Tries / #Stdnts ]'; - $Ptr .= ' |
| '; - $Ptr .= '#YES | '; - $Ptr .= 'Number of students solved the problem correctly.'; - $Ptr .= ' |
| '; - $Ptr .= '#yes | '; - $Ptr .= 'Number of students solved the problem by override.'; - $Ptr .= ' |
| '; - $Ptr .= '%Wrong | '; - $Ptr .= 'Percentage of students who tried to solve the problem '; - $Ptr .= 'but is still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]'; - $Ptr .= ' |
| '; - $Ptr .= 'DoDiff | '; - $Ptr .= 'Degree of Difficulty of the problem. '; - $Ptr .= '[ 1 - ((#YES+#yes) / Tries) ]'; - $Ptr .= ' |
| '; - $Ptr .= 'S.D. | '; - $Ptr .= 'Standard Deviation of the tries. '; - $Ptr .= '[ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1) '; - $Ptr .= 'where Xi denotes every student\'s tries ]'; - $Ptr .= ' |
| '; - $Ptr .= 'Skew. | '; - $Ptr .= 'Skewness of the students tries.'; - $Ptr .= '[(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]'; - $Ptr .= ' |
| '; - $Ptr .= 'Dis.F. | '; - $Ptr .= 'Discrimination Factor: A Standard for evaluating the ';
- $Ptr .= 'problem according to a Criterion '; - $Ptr .= '[Criterion to group students into %27 Upper Students - '; - $Ptr .= 'and %27 Lower Students] '; - $Ptr .= '1st Criterion for Sorting the Students: '; - $Ptr .= 'Sum of Partial Credit Awarded / Total Number of Tries '; - $Ptr .= '2nd Criterion for Sorting the Students: '; - $Ptr .= 'Total number of Correct Answers / Total Number of Tries'; - $Ptr .= ' |
| Disc. | '; - $Ptr .= 'Number of Students had at least one discussion.'; - $Ptr .= ' |
+ +=item [Criterion to group students into %27 Upper Students - +and %27 Lower Students] +1st Criterion for Sorting the Students: +Sum of Partial Credit Awarded / Total Number of Tries +2nd Criterion for Sorting the Students: +Total number of Correct Answers / Total Number of Tries + +=item Disc. +Number of Students had at least one discussion. + +=back + +=cut -#---- END Problem Statistics Web Page ---------------------------------------- +############################################################ +############################################################ 1; __END__