1: # The LearningOnline Network with CAPA
2: #
3: # $Id: lonproblemstatistics.pm,v 1.81 2004/04/01 21:35:52 matthew Exp $
4: #
5: # Copyright Michigan State University Board of Trustees
6: #
7: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
8: #
9: # LON-CAPA is free software; you can redistribute it and/or modify
10: # it under the terms of the GNU General Public License as published by
11: # the Free Software Foundation; either version 2 of the License, or
12: # (at your option) any later version.
13: #
14: # LON-CAPA is distributed in the hope that it will be useful,
15: # but WITHOUT ANY WARRANTY; without even the implied warranty of
16: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17: # GNU General Public License for more details.
18: #
19: # You should have received a copy of the GNU General Public License
20: # along with LON-CAPA; if not, write to the Free Software
21: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22: #
23: # /home/httpd/html/adm/gpl.txt
24: #
25: # http://www.lon-capa.org/
26: #
27: # (Navigate problems for statistical reports
28: #
29: ###############################################
30: ###############################################
31:
32: =pod
33:
34: =head1 NAME
35:
36: lonproblemstatistics
37:
38: =head1 SYNOPSIS
39:
40: Routines to present problem statistics to instructors via tables,
41: Excel files, and plots.
42:
43: =over 4
44:
45: =cut
46:
47: ###############################################
48: ###############################################
49:
50: package Apache::lonproblemstatistics;
51:
52: use strict;
53: use Apache::lonnet();
54: use Apache::loncommon();
55: use Apache::lonhtmlcommon;
56: use Apache::loncoursedata;
57: use Apache::lonstatistics;
58: use Apache::lonlocal;
59: use Spreadsheet::WriteExcel;
60: use Apache::lonstathelpers();
61: use Time::HiRes;
62:
63: my @StatsArray;
64: my %SeqStat; # keys are symbs, values are hash refs
65:
66: ##
67: ## Localization notes:
68: ##
69: ## in @Fields[0]->{'long_title'} is placed in Excel files and is used as the
70: ## header for plots created with Graph.pm, both of which more than likely do
71: ## not support localization.
72: ##
73: #
74: #
75: ##
76: ## Description of Field attributes
77: ##
78: ## Attribute Required Value Meaning or Use
79: ##
80: ## name yes any scalar Used to uniquely identify field
81: ## title yes any scalar This is what the user sees to identify
82: ## the field. Passed through &mt().
83: ## long_title yes any scalar Used as graph heading and in excel
84: ## output. NOT translated
85: ## align no (left|right|center) HTML cell contents alignment
86: ## color yes html color HTML cell background color
87: ## used to visually group statistics
88: ## special no (link) Indicates a link, target is name.link
89: ## Currently set in &get_statistics()
90: ## graphable no (yes|no) Can a bar graph of the field be
91: ## produced?
92: ## sortable no (yes|no) Should a sort link be put in the
93: ## column header?
94: ## selectable yes (yes|no) Can the column be removed from the
95: ## statistics display?
96: ## selected yes (yes|no) Is the column selected by default?
97: ##
98: my @Fields = (
99: { name => 'problem_num',
100: title => 'P#',
101: align => 'right',
102: color => '#FFFFE6',
103: selectable => 'no',
104: defaultselected => 'yes',
105: },
106: { name => 'container',
107: title => 'Sequence or Folder',
108: align => 'left',
109: color => '#FFFFE6',
110: sortable => 'yes',
111: selectable => 'no',
112: defaultselected => 'yes',
113: },
114: { name => 'title',
115: title => 'Title',
116: align => 'left',
117: color => '#FFFFE6',
118: special => 'link',
119: sortable => 'yes',
120: selectable => 'no',
121: defaultselected => 'yes',
122: },
123: { name => 'part',
124: title => 'Part',
125: align => 'left',
126: color => '#FFFFE6',
127: selectable => 'no',
128: defaultselected => 'yes',
129: },
130: { name => 'num_students',
131: title => '#Stdnts',
132: align => 'right',
133: color => '#EEFFCC',
134: format => '%d',
135: sortable => 'yes',
136: graphable => 'yes',
137: long_title => 'Number of Students Attempting Problem',
138: selectable => 'yes',
139: defaultselected => 'yes',
140: },
141: { name => 'tries',
142: title => 'Tries',
143: align => 'right',
144: color => '#EEFFCC',
145: format => '%d',
146: sortable => 'yes',
147: graphable => 'yes',
148: long_title => 'Total Number of Tries',
149: selectable => 'yes',
150: defaultselected => 'yes',
151: },
152: { name => 'max_tries',
153: title => 'Max Tries',
154: align => 'right',
155: color => '#DDFFFF',
156: format => '%d',
157: sortable => 'yes',
158: graphable => 'yes',
159: long_title => 'Maximum Number of Tries',
160: selectable => 'yes',
161: defaultselected => 'yes',
162: },
163: { name => 'min_tries',
164: title => 'Min Tries',
165: align => 'right',
166: color => '#DDFFFF',
167: format => '%d',
168: sortable => 'yes',
169: graphable => 'yes',
170: long_title => 'Minumum Number of Tries',
171: selectable => 'yes',
172: defaultselected => 'yes',
173: },
174: { name => 'mean_tries',
175: title => 'Mean Tries',
176: align => 'right',
177: color => '#DDFFFF',
178: format => '%5.2f',
179: sortable => 'yes',
180: graphable => 'yes',
181: long_title => 'Average Number of Tries',
182: selectable => 'yes',
183: defaultselected => 'yes',
184: },
185: { name => 'std_tries',
186: title => 'S.D. tries',
187: align => 'right',
188: color => '#DDFFFF',
189: format => '%5.2f',
190: sortable => 'yes',
191: graphable => 'yes',
192: long_title => 'Standard Deviation of Number of Tries',
193: selectable => 'yes',
194: defaultselected => 'yes',
195: },
196: { name => 'skew_tries',
197: title => 'Skew Tries',
198: align => 'right',
199: color => '#DDFFFF',
200: format => '%5.2f',
201: sortable => 'yes',
202: graphable => 'yes',
203: long_title => 'Skew of Number of Tries',
204: selectable => 'yes',
205: defaultselected => 'no',
206: },
207: { name => 'num_solved',
208: title => '#YES',
209: align => 'right',
210: color => '#FFDDDD',
211: format => '%4.1f',# format => '%d',
212: sortable => 'yes',
213: graphable => 'yes',
214: long_title => 'Number of Students able to Solve',
215: selectable => 'yes',
216: defaultselected => 'yes',
217: },
218: { name => 'num_override',
219: title => '#yes',
220: align => 'right',
221: color => '#FFDDDD',
222: format => '%4.1f',# format => '%d',
223: sortable => 'yes',
224: graphable => 'yes',
225: long_title => 'Number of Students given Override',
226: selectable => 'yes',
227: defaultselected => 'yes',
228: },
229: { name => 'num_wrong',
230: title => '#Wrng',
231: align => 'right',
232: color => '#FFDDDD',
233: format => '%4.1f',
234: sortable => 'yes',
235: graphable => 'yes',
236: long_title => 'Percent of students whose final answer is wrong',
237: selectable => 'yes',
238: defaultselected => 'yes',
239: },
240: { name => 'deg_of_diff',
241: title => 'DoDiff',
242: align => 'right',
243: color => '#FFFFE6',
244: format => '%5.2f',
245: sortable => 'yes',
246: graphable => 'yes',
247: long_title => 'Degree of Difficulty'.
248: '[ 1 - ((#YES+#yes) / Tries) ]',
249: selectable => 'yes',
250: defaultselected => 'yes',
251: },
252: { name => 'deg_of_disc',
253: title => 'DoDisc',
254: align => 'right',
255: color => '#FFFFE6',
256: format => '%4.2f',
257: sortable => 'yes',
258: graphable => 'yes',
259: long_title => 'Degree of Discrimination',
260: selectable => 'yes',
261: defaultselected => 'no',
262: },
263: );
264:
265: my @SeqFields = (
266: { name => 'title',
267: title => 'Sequence',
268: align => 'left',
269: color => '#FFFFE6',
270: special => 'no',
271: sortable => 'no',
272: selectable => 'yes',
273: defaultselected => 'no',
274: },
275: { name => 'items',
276: title => '#Items',
277: align => 'right',
278: color => '#FFFFE6',
279: format => '%4d',
280: sortable => 'no',
281: graphable => 'no',
282: long_title => 'Number of Items in Sequence',
283: selectable => 'yes',
284: defaultselected => 'no',
285: },
286: { name => 'scoremean',
287: title => 'Score Mean',
288: align => 'right',
289: color => '#FFFFE6',
290: format => '%4.2f',
291: sortable => 'no',
292: graphable => 'no',
293: long_title => 'Mean Sequence Score',
294: selectable => 'yes',
295: defaultselected => 'no',
296: },
297: { name => 'scorestd',
298: title => 'Score STD',
299: align => 'right',
300: color => '#FFFFE6',
301: format => '%4.2f',
302: sortable => 'no',
303: graphable => 'no',
304: long_title => 'Standard Deviation of Sequence Scores',
305: selectable => 'yes',
306: defaultselected => 'no',
307: },
308: { name => 'scoremax',
309: title => 'Score Max',
310: align => 'right',
311: color => '#FFFFE6',
312: format => '%4.2f',
313: sortable => 'no',
314: graphable => 'no',
315: long_title => 'Maximum Sequence Score',
316: selectable => 'yes',
317: defaultselected => 'no',
318: },
319: { name => 'scoremin',
320: title => 'Score Min',
321: align => 'right',
322: color => '#FFFFE6',
323: format => '%4.2f',
324: sortable => 'no',
325: graphable => 'no',
326: long_title => 'Minumum Sequence Score',
327: selectable => 'yes',
328: defaultselected => 'no',
329: },
330: { name => 'scorecount',
331: title => 'Score N',
332: align => 'right',
333: color => '#FFFFE6',
334: format => '%4d',
335: sortable => 'no',
336: graphable => 'no',
337: long_title => 'Number of Students in score computations',
338: selectable => 'yes',
339: defaultselected => 'no',
340: },
341: { name => 'countmean',
342: title => 'Count Mean',
343: align => 'right',
344: color => '#FFFFFF',
345: format => '%4.2f',
346: sortable => 'no',
347: graphable => 'no',
348: long_title => 'Mean Sequence Score',
349: selectable => 'yes',
350: defaultselected => 'no',
351: },
352: { name => 'countstd',
353: title => 'Count STD',
354: align => 'right',
355: color => '#FFFFFF',
356: format => '%4.2f',
357: sortable => 'no',
358: graphable => 'no',
359: long_title => 'Standard Deviation of Sequence Scores',
360: selectable => 'yes',
361: defaultselected => 'no',
362: },
363: { name => 'countmax',
364: title => 'Count Max',
365: align => 'right',
366: color => '#FFFFFF',
367: format => '%4.2f',
368: sortable => 'no',
369: graphable => 'no',
370: long_title => 'Maximum Number of Correct Problems',
371: selectable => 'yes',
372: defaultselected => 'no',
373: },
374: { name => 'countmin',
375: title => 'Count Min',
376: align => 'right',
377: color => '#FFFFFF',
378: format => '%4.2f',
379: sortable => 'no',
380: graphable => 'no',
381: long_title => 'Minumum Number of Correct Problems',
382: selectable => 'yes',
383: defaultselected => 'no',
384: },
385: { name => 'count',
386: title => 'Count N',
387: align => 'right',
388: color => '#FFFFFF',
389: format => '%4d',
390: sortable => 'no',
391: graphable => 'no',
392: long_title => 'Number of Students in score computations',
393: selectable => 'yes',
394: defaultselected => 'no',
395: },
396: { name => 'KR-21',
397: title => 'KR-21',
398: align => 'right',
399: color => '#FFAAAA',
400: format => '%4.2f',
401: sortable => 'no',
402: graphable => 'no',
403: long_title => 'KR-21 reliability statistic',
404: selectable => 'yes',
405: defaultselected => 'no',
406: },
407: );
408:
409: my %SelectedFields;
410:
411: sub parse_field_selection {
412: #
413: # Pull out the defaults
414: if (! defined($ENV{'form.fieldselections'})) {
415: $ENV{'form.fieldselections'} = [];
416: foreach my $field (@Fields) {
417: next if ($field->{'selectable'} ne 'yes');
418: if ($field->{'defaultselected'} eq 'yes') {
419: push(@{$ENV{'form.fieldselections'}},$field->{'name'});
420: }
421: }
422: }
423: #
424: # Make sure the data we are plotting is there
425: my %NeededFields;
426: if (exists($ENV{'form.plot'}) && $ENV{'form.plot'} ne '' &&
427: $ENV{'form.plot'} ne 'none') {
428: if ($ENV{'form.plot'} eq 'degrees') {
429: $NeededFields{'deg_of_diff'}++;
430: $NeededFields{'deg_of_disc'}++;
431: } elsif ($ENV{'form.plot'} eq 'tries statistics') {
432: $NeededFields{'mean_tries'}++;
433: $NeededFields{'std_tries'}++;
434: $NeededFields{'problem_num'}++;
435: } else {
436: $NeededFields{$ENV{'form.plot'}}++;
437: }
438: }
439: #
440: # This should not happen, but in case it does...
441: if (ref($ENV{'form.fieldselections'}) ne 'ARRAY') {
442: $ENV{'form.fieldselections'} = [$ENV{'form.fieldselections'}];
443: }
444: #
445: # Set the field data and the selected fields (for easier checking)
446: undef(%SelectedFields);
447: foreach my $field (@Fields) {
448: if ($field->{'selectable'} ne 'yes') {
449: $field->{'selected'} = 'yes';
450: } else {
451: $field->{'selected'} = 'no';
452: }
453: if (exists($NeededFields{$field->{'name'}})) {
454: $field->{'selected'} = 'yes';
455: $SelectedFields{$field->{'name'}}++;
456: }
457: foreach my $selection (@{$ENV{'form.fieldselections'}}) {
458: if ($selection eq $field->{'name'} || $selection eq 'all') {
459: $field->{'selected'} = 'yes';
460: $SelectedFields{$field->{'name'}}++;
461: }
462: }
463: }
464: return;
465: }
466:
467: sub field_selection_input {
468: my $Str = '<select name="fieldselections" multiple size="5">'."\n";
469: $Str .= '<option value="all">all</option>'."\n";
470: foreach my $field (@Fields) {
471: next if ($field->{'selectable'} ne 'yes');
472: $Str .= ' <option value="'.$field->{'name'}.'" ';
473: if ($field->{'selected'} eq 'yes') {
474: $Str .= 'selected ';
475: }
476: $Str .= '>'.$field->{'title'}.'</option>'."\n";
477: }
478: $Str .= "</select>\n";
479: }
480:
481: ###############################################
482: ###############################################
483:
484: =pod
485:
486: =item &CreateInterface()
487:
488: Create the main intereface for the statistics page. Allows the user to
489: select sections, maps, and output.
490:
491: =cut
492:
493: ###############################################
494: ###############################################
495: sub CreateInterface {
496: #
497: &parse_field_selection();
498: #
499: my $Str = '';
500: $Str .= &Apache::lonhtmlcommon::breadcrumbs
501: (undef,'Overall Problem Statistics','Statistics_Overall_Key');
502: $Str .= '<table cellspacing="5">'."\n";
503: $Str .= '<tr>';
504: $Str .= '<td align="center"><b>'.&mt('Sections').'</b></td>';
505: $Str .= '<td align="center"><b>'.&mt('Enrollment Status').'</b></td>';
506: $Str .= '<td align="center"><b>'.&mt('Sequences and Folders').'</b></td>';
507: $Str .= '<td align="center"><b>'.&mt('Statistics').'</b></td>';
508: $Str .= '<td rowspan="2">'.
509: &Apache::lonstathelpers::limit_by_time_form().'</td>';
510: $Str .= '</tr>'."\n";
511: #
512: $Str .= '<tr><td align="center">'."\n";
513: $Str .= &Apache::lonstatistics::SectionSelect('Section','multiple',5);
514: $Str .= '</td><td align="center">';
515: $Str .= &Apache::lonhtmlcommon::StatusOptions(undef,undef,5);
516: $Str .= '</td><td align="center">';
517: #
518: my $only_seq_with_assessments = sub {
519: my $s=shift;
520: if ($s->{'num_assess'} < 1) {
521: return 0;
522: } else {
523: return 1;
524: }
525: };
526: $Str .= &Apache::lonstatistics::MapSelect('Maps','multiple,all',5,
527: $only_seq_with_assessments);
528: $Str .= '</td><td>'.&field_selection_input();
529: $Str .= '</td></tr>'."\n";
530: $Str .= '</table>'."\n";
531: $Str .= '<input type="submit" name="GenerateStatistics" value="'.
532: &mt('Generate Statistics').'" />';
533: $Str .= ' 'x5;
534: $Str .= 'Plot '.&plot_dropdown().(' 'x10);
535: $Str .= '<input type="submit" name="ClearCache" value="'.
536: &mt('Clear Caches').'" />';
537: $Str .= ' 'x5;
538: $Str .= '<input type="submit" name="UpdateCache" value="'.
539: &mt('Update Student Data').'" />';
540: $Str .= ' 'x5;
541: $Str .= '<input type="submit" name="Excel" value="'.
542: &mt('Produce Excel Output').'" />';
543: $Str .= ' 'x5;
544: return $Str;
545: }
546:
547: ###############################################
548: ###############################################
549:
550: =pod
551:
552: =item &BuildProblemStatisticsPage()
553:
554: Main interface to problem statistics.
555:
556: =cut
557:
558: ###############################################
559: ###############################################
560: sub BuildProblemStatisticsPage {
561: my ($r,$c)=@_;
562: #
563: my %Saveable_Parameters = ('Status' => 'scalar',
564: 'statsoutputmode' => 'scalar',
565: 'Section' => 'array',
566: 'StudentData' => 'array',
567: 'Maps' => 'array',
568: 'fieldselections'=> 'array');
569: &Apache::loncommon::store_course_settings('statistics',
570: \%Saveable_Parameters);
571: &Apache::loncommon::restore_course_settings('statistics',
572: \%Saveable_Parameters);
573: #
574: &Apache::lonstatistics::PrepareClasslist();
575: #
576: # Clear the package variables
577: undef(@StatsArray);
578: undef(%SeqStat);
579: #
580: # Finally let the user know we are here
581: my $interface = &CreateInterface();
582: $r->print($interface);
583: $r->print('<input type="hidden" name="sortby" value="'.$ENV{'form.sortby'}.
584: '" />');
585: #
586: if (! exists($ENV{'form.statsfirstcall'})) {
587: $r->print('<input type="hidden" name="statsfirstcall" value="yes" />');
588: $r->print('<h3>'.
589: &mt('Press "Generate Statistics" when you are ready.').
590: '</h3><p>'.
591: &mt('It may take some time to update the student data '.
592: 'for the first analysis. Future analysis this session '.
593: ' will not have this delay.').
594: '</p>');
595: return;
596: } elsif ($ENV{'form.statsfirstcall'} eq 'yes' ||
597: exists($ENV{'form.UpdateCache'}) ||
598: exists($ENV{'form.ClearCache'}) ) {
599: $r->print('<input type="hidden" name="statsfirstcall" value="no" />');
600: &Apache::lonstatistics::Gather_Student_Data($r);
601: } else {
602: $r->print('<input type="hidden" name="statsfirstcall" value="no" />');
603: }
604: $r->rflush();
605: #
606: # This probably does not need to be done each time we are called, but
607: # it does not slow things down noticably.
608: &Apache::loncoursedata::populate_weight_table();
609: #
610: if (exists($ENV{'form.Excel'})) {
611: &Excel_output($r);
612: } else {
613: my $count = 0;
614: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
615: $count += $seq->{'num_assess_parts'};
616: }
617: if ($count > 10) {
618: $r->print('<h2>'.
619: &mt('Compiling statistics for [_1] problems',$count).
620: '</h2>');
621: if ($count > 30) {
622: $r->print('<h3>'.&mt('This will take some time.').'</h3>');
623: }
624: $r->rflush();
625: }
626: #
627: my $sortby = $ENV{'form.sortby'};
628: $sortby = 'container' if (! defined($sortby) || $sortby =~ /^\s*$/);
629: my $plot = $ENV{'form.plot'};
630: if ($plot eq '' || $plot eq 'none') {
631: undef($plot);
632: }
633: if ($sortby eq 'container' && ! defined($plot)) {
634: &output_sequence_statistics($r);
635: &output_html_by_sequence($r);
636: } else {
637: if (defined($plot)) {
638: &make_plot($r,$plot);
639: }
640: &output_html_stats($r);
641: &output_sequence_statistics($r);
642: }
643: }
644: return;
645: }
646:
647: sub output_sequence_statistics {
648: my ($r) = @_;
649: my $c=$r->connection();
650: $r->print('<h2>'.&mt('Sequence Statistics').'</h2>');
651: $r->print('<table border="0"><tr><td bgcolor="#777777">'."\n".
652: '<table border="0" cellpadding="3">'."\n".
653: '<tr bgcolor="#FFFFE6">');
654: $r->print(&sequence_html_header());
655: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
656: last if ($c->aborted);
657: next if ($seq->{'num_assess'} < 1);
658: &compute_sequence_statistics($seq);
659: $r->print(&sequence_html_output($seq));
660: }
661: $r->print('</table>');
662: $r->print('</table>');
663: $r->rflush();
664: return;
665: }
666:
667:
668: ##########################################################
669: ##########################################################
670: ##
671: ## HTML output routines
672: ##
673: ##########################################################
674: ##########################################################
675: sub output_html_by_sequence {
676: my ($r) = @_;
677: my $c = $r->connection();
678: $r->print(&html_preamble());
679: #
680: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
681: last if ($c->aborted);
682: next if ($seq->{'num_assess'} < 1);
683: $r->print("<h3>".$seq->{'title'}."</h3>".
684: '<table border="0"><tr><td bgcolor="#777777">'."\n".
685: '<table border="0" cellpadding="3">'."\n".
686: '<tr bgcolor="#FFFFE6">'.
687: &statistics_table_header('no container')."</tr>\n");
688: my @Data = &compute_statistics_on_sequence($seq);
689: foreach my $data (@Data) {
690: $r->print('<tr>'.&statistics_html_table_data($data,
691: 'no container').
692: "</tr>\n");
693: }
694: $r->print('</table>'."\n".'</table>'."\n");
695: $r->rflush();
696: }
697: return;
698: }
699:
700: sub output_html_stats {
701: my ($r)=@_;
702: &compute_all_statistics($r);
703: $r->print(&html_preamble());
704: &sort_data($ENV{'form.sortby'});
705: #
706: my $count=0;
707: foreach my $data (@StatsArray) {
708: if ($count++ % 50 == 0) {
709: $r->print("</table>\n</table>\n");
710: $r->print('<table border="0"><tr><td bgcolor="#777777">'."\n".
711: '<table border="0" cellpadding="3">'."\n".
712: '<tr bgcolor="#FFFFE6">'.
713: '<tr bgcolor="#FFFFE6">'.
714: &statistics_table_header().
715: "</tr>\n");
716: }
717: $r->print('<tr>'.&statistics_html_table_data($data)."</tr>\n");
718: }
719: $r->print("</table>\n</table>\n");
720: return;
721: }
722:
723: sub html_preamble {
724: my $Str='';
725: $Str .= "<h2>".
726: $ENV{'course.'.$ENV{'request.course.id'}.'.description'}.
727: "</h2>\n";
728: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
729: if (defined($starttime) || defined($endtime)) {
730: # Inform the user what the time limits on the data are.
731: $Str .= '<h3>'.&mt('Statistics on submissions from [_1] to [_2]',
732: &Apache::lonlocal::locallocaltime($starttime),
733: &Apache::lonlocal::locallocaltime($endtime)
734: ).'</h3>';
735: }
736: $Str .= "<h3>".&mt('Compiled on [_1]',
737: &Apache::lonlocal::locallocaltime(time))."</h3>";
738: return $Str;
739: }
740:
741:
742: ###############################################
743: ###############################################
744: ##
745: ## Misc HTML output routines
746: ##
747: ###############################################
748: ###############################################
749: sub statistics_html_table_data {
750: my ($data,$options) = @_;
751: my $row = '';
752: foreach my $field (@Fields) {
753: next if ($options =~ /no $field->{'name'}/);
754: next if ($field->{'selected'} ne 'yes');
755: $row .= '<td bgcolor="'.$field->{'color'}.'"';
756: if (exists($field->{'align'})) {
757: $row .= ' align="'.$field->{'align'}.'"';
758: }
759: $row .= '>';
760: if (exists($field->{'special'}) && $field->{'special'} eq 'link') {
761: $row .= '<a href="'.$data->{$field->{'name'}.'.link'}.'">';
762: }
763: if (exists($field->{'format'})) {
764: $row .= sprintf($field->{'format'},$data->{$field->{'name'}});
765: } else {
766: $row .= $data->{$field->{'name'}};
767: }
768: if (exists($field->{'special'}) && $field->{'special'} eq 'link') {
769: $row.= '</a>';
770: }
771: $row .= '</td>';
772: }
773: return $row;
774: }
775:
776: sub statistics_table_header {
777: my ($options) = @_;
778: my $header_row;
779: foreach my $field (@Fields) {
780: next if ($options =~ /no $field->{'name'}/);
781: next if ($field->{'selected'} ne 'yes');
782: $header_row .= '<th>';
783: if (exists($field->{'sortable'}) && $field->{'sortable'} eq 'yes') {
784: $header_row .= '<a href="javascript:'.
785: 'document.Statistics.sortby.value='."'".$field->{'name'}."'".
786: ';document.Statistics.submit();">';
787: }
788: $header_row .= &mt($field->{'title'});
789: if ($options =~ /sortable/) {
790: $header_row.= '</a>';
791: }
792: if ($options !~ /no plots/ &&
793: exists($field->{'graphable'}) &&
794: $field->{'graphable'} eq 'yes') {
795: $header_row.=' (';
796: $header_row .= '<a href="javascript:'.
797: "document.Statistics.plot.value='$field->{'name'}'".
798: ';document.Statistics.submit();">';
799: $header_row .= &mt('plot').'</a>)';
800: }
801: $header_row .= '</th>';
802: }
803: return $header_row;
804: }
805:
806: sub sequence_html_header {
807: my $Str .= '<tr>';
808: foreach my $field (@SeqFields) {
809: # next if ($field->{'selected'} ne 'yes');
810: $Str .= '<th bgcolor="'.$field->{'color'}.'"';
811: $Str .= '>'.$field->{'title'}.'</th>';
812: }
813: $Str .= '</tr>';
814: return $Str;
815: }
816:
817:
818: sub sequence_html_output {
819: my ($seq) = @_;
820: my $data = $SeqStat{$seq->{'symb'}};
821: # $SeqStat{$symb}->{'max'}
822: # $SeqStat{$symb}->{'min'}
823: # $SeqStat{$symb}->{'mean'}
824: # $SeqStat{$symb}->{'std'}
825: # $SeqStat{$symb}->{'count'}
826: # $SeqStat{$symb}->{'max_possible'}
827: my $row = '<tr>';
828: foreach my $field (@SeqFields) {
829: # next if ($field->{'selected'} ne 'yes');
830: $row .= '<td bgcolor="'.$field->{'color'}.'"';
831: if (exists($field->{'align'})) {
832: $row .= ' align="'.$field->{'align'}.'"';
833: }
834: $row .= '>';
835: if (exists($field->{'format'})) {
836: $row .= sprintf($field->{'format'},$data->{$field->{'name'}});
837: } else {
838: $row .= $data->{$field->{'name'}};
839: }
840: $row .= '</td>';
841: }
842: $row .= '</tr>'."\n";
843: return $row;
844: }
845:
846: ####################################################
847: ####################################################
848: ##
849: ## Plotting Routines
850: ##
851: ####################################################
852: ####################################################
853: sub make_plot {
854: my ($r,$plot) = @_;
855: &compute_all_statistics($r);
856: &sort_data($ENV{'form.sortby'});
857: if ($plot eq 'degrees') {
858: °rees_plot($r);
859: } elsif ($plot eq 'tries statistics') {
860: &tries_data_plot($r);
861: } else {
862: &make_single_stat_plot($r,$plot);
863: }
864: return;
865: }
866:
867: sub make_single_stat_plot {
868: my ($r,$datafield) = @_;
869: #
870: my $title; my $yaxis;
871: foreach my $field (@Fields) {
872: next if ($field->{'name'} ne $datafield);
873: $title = $field->{'long_title'};
874: $yaxis = $field->{'title'};
875: last;
876: }
877: if ($title eq '' || $yaxis eq '') {
878: # datafield is something we do not know enough about to plot
879: $r->print('<h3>'.
880: &mt('Unable to plot the requested statistic.').
881: '</h3>');
882: return;
883: }
884: #
885: # Build up the data sets to plot
886: my @Labels;
887: my @Data;
888: my $max = 1;
889: foreach my $data (@StatsArray) {
890: push(@Labels,$data->{'problem_num'});
891: push(@Data,$data->{$datafield});
892: if ($data->{$datafield}>$max) {
893: $max = $data->{$datafield};
894: }
895: }
896: foreach (1,2,3,4,5,10,15,20,25,40,50,75,100,150,200,250,300,500,600,750,
897: 1000,1500,2000,2500,3000,3500,4000,5000,7500,10000,15000,20000) {
898: if ($max <= $_) {
899: $max = $_;
900: last;
901: }
902: }
903: if ($max > 20000) {
904: $max = 10000*(int($max/10000)+1);
905: }
906: #
907: $r->print("<p>".&Apache::loncommon::DrawBarGraph($title,
908: 'Problem Number',
909: $yaxis,
910: $max,
911: undef, # colors
912: \@Labels,
913: \@Data)."</p>\n");
914: return;
915: }
916:
917: sub degrees_plot {
918: my ($r)=@_;
919: my $count = scalar(@StatsArray);
920: my $width = 50 + 10*$count;
921: $width = 300 if ($width < 300);
922: my $height = 300;
923: my $plot = '';
924: my $ymax = 0;
925: my $ymin = 0;
926: my @Disc; my @Diff; my @Labels;
927: foreach my $data (@StatsArray) {
928: push(@Labels,$data->{'problem_num'});
929: my $disc = $data->{'deg_of_disc'};
930: my $diff = $data->{'deg_of_diff'};
931: push(@Disc,$disc);
932: push(@Diff,$diff);
933: #
934: $ymin = $disc if ($ymin > $disc);
935: $ymin = $diff if ($ymin > $diff);
936: $ymax = $disc if ($ymax < $disc);
937: $ymax = $diff if ($ymax < $diff);
938: }
939: #
940: # Make sure we show relevant information.
941: if ($ymin < 0) {
942: if (abs($ymin) < 0.05) {
943: $ymin = 0;
944: } else {
945: $ymin = -1;
946: }
947: }
948: if ($ymax > 0) {
949: if (abs($ymax) < 0.05) {
950: $ymax = 0;
951: } else {
952: $ymax = 1;
953: }
954: }
955: #
956: my $xmax = $Labels[-1];
957: if ($xmax > 50) {
958: if ($xmax % 10 != 0) {
959: $xmax = 10 * (int($xmax/10)+1);
960: }
961: } else {
962: if ($xmax % 5 != 0) {
963: $xmax = 5 * (int($xmax/5)+1);
964: }
965: }
966: #
967: my $discdata .= '<data>'.join(',',@Labels).'</data>'.$/.
968: '<data>'.join(',',@Disc).'</data>'.$/;
969: #
970: my $diffdata .= '<data>'.join(',',@Labels).'</data>'.$/.
971: '<data>'.join(',',@Diff).'</data>'.$/;
972: #
973: my $title = 'Degree of Discrimination\nand Degree of Difficulty';
974: if ($xmax > 50) {
975: $title = 'Degree of Discrimination and Degree of Difficulty';
976: }
977: #
978: $plot=<<"END";
979: <gnuplot
980: texfont="10"
981: fgcolor="x000000"
982: plottype="Cartesian"
983: font="large"
984: grid="on"
985: align="center"
986: border="on"
987: transparent="on"
988: alttag="Degree of Discrimination and Degree of Difficulty Plot"
989: samples="100"
990: bgcolor="xffffff"
991: height="$height"
992: width="$width">
993: <key
994: pos="top right"
995: title=""
996: box="off" />
997: <title>$title</title>
998: <axis xmin="0" ymin="$ymin" xmax="$xmax" ymax="$ymax" color="x000000" />
999: <xlabel>Problem Number</xlabel>
1000: <curve
1001: linestyle="linespoints"
1002: name="DoDisc"
1003: pointtype="0"
1004: color="x000000">
1005: $discdata
1006: </curve>
1007: <curve
1008: linestyle="linespoints"
1009: name="DoDiff"
1010: pointtype="0"
1011: color="xFF0000">
1012: $diffdata
1013: </curve>
1014: </gnuplot>
1015: END
1016: my $plotresult =
1017: '<p>'.&Apache::lonxml::xmlparse($r,'web',$plot).'</p>'.$/;
1018: $r->print($plotresult);
1019: return;
1020: }
1021:
1022: sub tries_data_plot {
1023: my ($r)=@_;
1024: my $count = scalar(@StatsArray);
1025: my $width = 50 + 10*$count;
1026: $width = 300 if ($width < 300);
1027: my $height = 300;
1028: my $plot = '';
1029: my @STD; my @Mean; my @Max; my @Min;
1030: my @Labels;
1031: my $ymax = 5;
1032: foreach my $data (@StatsArray) {
1033: my $max = $data->{'mean_tries'} + $data->{'std_tries'};
1034: $ymax = $max if ($ymax < $max);
1035: $ymax = $max if ($ymax < $max);
1036: push(@Labels,$data->{'problem_num'});
1037: push(@STD,$data->{'std_tries'});
1038: push(@Mean,$data->{'mean_tries'});
1039: }
1040: #
1041: # Make sure we show relevant information.
1042: my $xmax = $Labels[-1];
1043: if ($xmax > 50) {
1044: if ($xmax % 10 != 0) {
1045: $xmax = 10 * (int($xmax/10)+1);
1046: }
1047: } else {
1048: if ($xmax % 5 != 0) {
1049: $xmax = 5 * (int($xmax/5)+1);
1050: }
1051: }
1052: $ymax = int($ymax)+1+2;
1053: #
1054: my $std_data .= '<data>'.join(',',@Labels).'</data>'.$/.
1055: '<data>'.join(',',@Mean).'</data>'.$/;
1056: #
1057: my $std_error_data .= '<data>'.join(',',@Labels).'</data>'.$/.
1058: '<data>'.join(',',@Mean).'</data>'.$/.
1059: '<data>'.join(',',@STD).'</data>'.$/;
1060: #
1061: my $title = 'Mean and S.D. of Tries';
1062: if ($xmax > 25) {
1063: $title = 'Mean and Standard Deviation of Tries';
1064: }
1065: #
1066: $plot=<<"END";
1067: <gnuplot
1068: texfont="10"
1069: fgcolor="x000000"
1070: plottype="Cartesian"
1071: font="large"
1072: grid="on"
1073: align="center"
1074: border="on"
1075: transparent="on"
1076: alttag="Mean and S.D of Tries Plot"
1077: samples="100"
1078: bgcolor="xffffff"
1079: height="$height"
1080: width="$width">
1081: <title>$title</title>
1082: <axis xmin="0" ymin="0" xmax="$xmax" ymax="$ymax" color="x000000" />
1083: <xlabel>Problem Number</xlabel>
1084: <ylabel>Number of Tries</ylabel>
1085: <curve
1086: linestyle="yerrorbars"
1087: name="S.D. Tries"
1088: pointtype="1"
1089: color="x666666">
1090: $std_error_data
1091: </curve>
1092: <curve
1093: linestyle="points"
1094: name="Mean Tries"
1095: pointtype="1"
1096: color="xCC4444">
1097: $std_data
1098: </curve>
1099: </gnuplot>
1100: END
1101: my $plotresult =
1102: '<p>'.&Apache::lonxml::xmlparse($r,'web',$plot).'</p>'.$/;
1103: $r->print($plotresult);
1104: return;
1105: }
1106:
1107: sub plot_dropdown {
1108: my $current = '';
1109: #
1110: if (defined($ENV{'form.plot'})) {
1111: $current = $ENV{'form.plot'};
1112: }
1113: #
1114: my @Additional_Plots = (
1115: { graphable=>'yes',
1116: name => 'degrees',
1117: title => 'Difficulty Indexes' },
1118: { graphable=>'yes',
1119: name => 'tries statistics',
1120: title => 'Tries Statistics' });
1121: #
1122: my $Str= "\n".'<select name="plot" size="1">';
1123: $Str .= '<option name="none"></option>'."\n";
1124: $Str .= '<option name="none2">none</option>'."\n";
1125: foreach my $field (@Additional_Plots,@Fields) {
1126: if (! exists($field->{'graphable'}) ||
1127: $field->{'graphable'} ne 'yes') {
1128: next;
1129: }
1130: $Str .= '<option value="'.$field->{'name'}.'"';
1131: if ($field->{'name'} eq $current) {
1132: $Str .= ' selected ';
1133: }
1134: $Str.= '>'.&mt($field->{'title'}).'</option>'."\n";
1135: }
1136: $Str .= '</select>'."\n";
1137: return $Str;
1138: }
1139:
1140: ###############################################
1141: ###############################################
1142: ##
1143: ## Excel output routines
1144: ##
1145: ###############################################
1146: ###############################################
1147: sub Excel_output {
1148: my ($r) = @_;
1149: $r->print('<h2>'.&mt('Preparing Excel Spreadsheet').'</h2>');
1150: ##
1151: ## Compute the statistics
1152: &compute_all_statistics($r);
1153: my $c = $r->connection;
1154: return if ($c->aborted());
1155: ##
1156: ## Create the excel workbook
1157: my $filename = '/prtspool/'.
1158: $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
1159: time.'_'.rand(1000000000).'.xls';
1160: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
1161: #
1162: # Create sheet
1163: my $excel_workbook = Spreadsheet::WriteExcel->new('/home/httpd'.$filename);
1164: #
1165: # Check for errors
1166: if (! defined($excel_workbook)) {
1167: $r->log_error("Error creating excel spreadsheet $filename: $!");
1168: $r->print(&mt("Problems creating new Excel file. ".
1169: "This error has been logged. ".
1170: "Please alert your LON-CAPA administrator."));
1171: return 0;
1172: }
1173: #
1174: # The excel spreadsheet stores temporary data in files, then put them
1175: # together. If needed we should be able to disable this (memory only).
1176: # The temporary directory must be specified before calling 'addworksheet'.
1177: # File::Temp is used to determine the temporary directory.
1178: $excel_workbook->set_tempdir($Apache::lonnet::tmpdir);
1179: #
1180: # Add a worksheet
1181: my $sheetname = $ENV{'course.'.$ENV{'request.course.id'}.'.description'};
1182: if (length($sheetname) > 31) {
1183: $sheetname = substr($sheetname,0,31);
1184: }
1185: my $excel_sheet = $excel_workbook->addworksheet(
1186: &Apache::loncommon::clean_excel_name($sheetname));
1187: ##
1188: ## Begin creating excel sheet
1189: ##
1190: my ($rows_output,$cols_output) = (0,0);
1191: #
1192: # Put the course description in the header
1193: $excel_sheet->write($rows_output,$cols_output++,
1194: $ENV{'course.'.$ENV{'request.course.id'}.'.description'});
1195: $cols_output += 3;
1196: #
1197: # Put a description of the sections listed
1198: my $sectionstring = '';
1199: my @Sections = @Apache::lonstatistics::SelectedSections;
1200: if (scalar(@Sections) > 1) {
1201: if (scalar(@Sections) > 2) {
1202: my $last = pop(@Sections);
1203: $sectionstring = "Sections ".join(', ',@Sections).', and '.$last;
1204: } else {
1205: $sectionstring = "Sections ".join(' and ',@Sections);
1206: }
1207: } else {
1208: if ($Sections[0] eq 'all') {
1209: $sectionstring = "All sections";
1210: } else {
1211: $sectionstring = "Section ".$Sections[0];
1212: }
1213: }
1214: $excel_sheet->write($rows_output,$cols_output++,$sectionstring);
1215: $cols_output += scalar(@Sections);
1216: #
1217: # Time restrictions
1218: my $time_string;
1219: if (defined($starttime)) {
1220: # call localtime but not lonlocal:locallocaltime because excel probably
1221: # cannot handle localized text. Probably.
1222: $time_string .= 'Data collected from '.localtime($time_string);
1223: if (defined($endtime)) {
1224: $time_string .= ' to '.localtime($endtime);
1225: }
1226: $time_string .= '.';
1227: } elsif (defined($endtime)) {
1228: # See note above about lonlocal:locallocaltime
1229: $time_string .= 'Data collected before '.localtime($endtime).'.';
1230: }
1231: #
1232: # Put the date in there too
1233: $excel_sheet->write($rows_output,$cols_output++,
1234: 'Compiled on '.localtime(time));
1235: #
1236: $rows_output++;
1237: $cols_output=0;
1238: #
1239: # Long Headers
1240: foreach my $field (@Fields) {
1241: next if ($field->{'name'} eq 'problem_num');
1242: next if ($field->{'selected'} ne 'yes');
1243: if (exists($field->{'long_title'})) {
1244: $excel_sheet->write($rows_output,$cols_output++,
1245: $field->{'long_title'});
1246: } else {
1247: $excel_sheet->write($rows_output,$cols_output++,'');
1248: }
1249: }
1250: $rows_output++;
1251: $cols_output=0;
1252: # Brief headers
1253: foreach my $field (@Fields) {
1254: next if ($field->{'selected'} ne 'yes');
1255: next if ($field->{'name'} eq 'problem_num');
1256: # Use english for excel as I am not sure how well excel handles
1257: # other character sets....
1258: $excel_sheet->write($rows_output,$cols_output++,$field->{'title'});
1259: }
1260: $rows_output++;
1261: foreach my $data (@StatsArray) {
1262: $cols_output=0;
1263: foreach my $field (@Fields) {
1264: next if ($field->{'selected'} ne 'yes');
1265: next if ($field->{'name'} eq 'problem_num');
1266: $excel_sheet->write($rows_output,$cols_output++,
1267: $data->{$field->{'name'}});
1268: }
1269: $rows_output++;
1270: }
1271: #
1272: $excel_workbook->close();
1273: #
1274: # Tell the user where to get their excel file
1275: $r->print('<br />'.
1276: '<a href="'.$filename.'">'.
1277: &mt('Your Excel Spreadsheet').'</a>'."\n");
1278: $r->rflush();
1279: return;
1280: }
1281:
1282: ##################################################
1283: ##################################################
1284: ##
1285: ## Statistics Gathering and Manipulation Routines
1286: ##
1287: ##################################################
1288: ##################################################
1289: sub compute_statistics_on_sequence {
1290: my ($seq) = @_;
1291: my @Data;
1292: foreach my $res (@{$seq->{'contents'}}) {
1293: next if ($res->{'type'} ne 'assessment');
1294: foreach my $part (@{$res->{'parts'}}) {
1295: #
1296: # This is where all the work happens
1297: my $data = &get_statistics($seq,$res,$part,scalar(@StatsArray)+1);
1298: push (@Data,$data);
1299: push (@StatsArray,$data);
1300: }
1301: }
1302: return @Data;
1303: }
1304:
1305: sub compute_all_statistics {
1306: my ($r) = @_;
1307: if (@StatsArray > 0) {
1308: # Assume we have already computed the statistics
1309: return;
1310: }
1311: my $c = $r->connection;
1312: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
1313: last if ($c->aborted);
1314: next if ($seq->{'num_assess'} < 1);
1315: &compute_statistics_on_sequence($seq);
1316: }
1317: }
1318:
1319: sub sort_data {
1320: my ($sortkey) = @_;
1321: return if (! @StatsArray);
1322: #
1323: # Sort the data
1324: my $sortby = undef;
1325: foreach my $field (@Fields) {
1326: if ($sortkey eq $field->{'name'}) {
1327: $sortby = $field->{'name'};
1328: }
1329: }
1330: if (! defined($sortby) || $sortby eq '' || $sortby eq 'problem_num') {
1331: $sortby = 'container';
1332: }
1333: if ($sortby ne 'container') {
1334: # $sortby is already defined, so we can charge ahead
1335: if ($sortby =~ /^(title|part)$/i) {
1336: # Alpha comparison
1337: @StatsArray = sort {
1338: lc($a->{$sortby}) cmp lc($b->{$sortby}) ||
1339: lc($a->{'title'}) cmp lc($b->{'title'}) ||
1340: lc($a->{'part'}) cmp lc($b->{'part'});
1341: } @StatsArray;
1342: } else {
1343: # Numerical comparison
1344: @StatsArray = sort {
1345: my $retvalue = 0;
1346: if ($b->{$sortby} eq 'nan') {
1347: if ($a->{$sortby} ne 'nan') {
1348: $retvalue = -1;
1349: } else {
1350: $retvalue = 0;
1351: }
1352: }
1353: if ($a->{$sortby} eq 'nan') {
1354: if ($b->{$sortby} ne 'nan') {
1355: $retvalue = 1;
1356: }
1357: }
1358: if ($retvalue eq '0') {
1359: $retvalue = $b->{$sortby} <=> $a->{$sortby} ||
1360: lc($a->{'title'}) <=> lc($b->{'title'}) ||
1361: lc($a->{'part'}) <=> lc($b->{'part'});
1362: }
1363: $retvalue;
1364: } @StatsArray;
1365: }
1366: }
1367: #
1368: # Renumber the data set
1369: my $count;
1370: foreach my $data (@StatsArray) {
1371: $data->{'problem_num'} = ++$count;
1372: }
1373: return;
1374: }
1375:
1376: ########################################################
1377: ########################################################
1378:
1379: =pod
1380:
1381: =item &get_statistics()
1382:
1383: Wrapper routine from the call to loncoursedata::get_problem_statistics.
1384: Calls lonstathelpers::get_time_limits() to limit the data set by time
1385: and &compute_discrimination_factor
1386:
1387: Inputs: $sequence, $resource, $part, $problem_num
1388:
1389: Returns: Hash reference with statistics data from
1390: loncoursedata::get_problem_statistics.
1391:
1392: =cut
1393:
1394: ########################################################
1395: ########################################################
1396: sub get_statistics {
1397: my ($sequence,$resource,$part,$problem_num) = @_;
1398: #
1399: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
1400: my $symb = $resource->{'symb'};
1401: my $courseid = $ENV{'request.course.id'};
1402: #
1403: my $data = &Apache::loncoursedata::get_problem_statistics
1404: (\@Apache::lonstatistics::SelectedSections,
1405: $Apache::lonstatistics::enrollment_status,
1406: $symb,$part,$courseid,$starttime,$endtime);
1407: $data->{'part'} = $part;
1408: $data->{'problem_num'} = $problem_num;
1409: $data->{'container'} = $sequence->{'title'};
1410: $data->{'title'} = $resource->{'title'};
1411: $data->{'title.link'} = $resource->{'src'}.'?symb='.
1412: &Apache::lonnet::escape($resource->{'symb'});
1413: #
1414: if ($SelectedFields{'deg_of_disc'}) {
1415: $data->{'deg_of_disc'} =
1416: &compute_discrimination_factor($resource,$part,$sequence);
1417: }
1418: return $data;
1419: }
1420:
1421: ###############################################
1422: ###############################################
1423:
1424: =pod
1425:
1426: =item &compute_discrimination_factor()
1427:
1428: Inputs: $Resource, $Sequence
1429:
1430: Returns: integer between -1 and 1
1431:
1432: =cut
1433:
1434: ###############################################
1435: ###############################################
1436: sub compute_discrimination_factor {
1437: my ($resource,$part,$sequence) = @_;
1438: my @Resources;
1439: foreach my $res (@{$sequence->{'contents'}}) {
1440: next if ($res->{'symb'} eq $resource->{'symb'});
1441: push (@Resources,$res->{'symb'});
1442: }
1443: #
1444: # rank
1445: my $ranking =
1446: &Apache::loncoursedata::rank_students_by_scores_on_resources
1447: (\@Resources,
1448: \@Apache::lonstatistics::SelectedSections,
1449: $Apache::lonstatistics::enrollment_status,undef);
1450: #
1451: # compute their percent scores on the problems in the sequence,
1452: my $number_to_grab = int(scalar(@{$ranking})/4);
1453: my $num_students = scalar(@{$ranking});
1454: my @BottomSet = map { $_->[&Apache::loncoursedata::RNK_student()];
1455: } @{$ranking}[0..$number_to_grab];
1456: my @TopSet =
1457: map {
1458: $_->[&Apache::loncoursedata::RNK_student()];
1459: } @{$ranking}[($num_students-$number_to_grab)..($num_students-1)];
1460: my ($bottom_sum,$bottom_max) =
1461: &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@BottomSet);
1462: my ($top_sum,$top_max) =
1463: &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@TopSet);
1464: my $deg_of_disc;
1465: if ($top_max == 0 || $bottom_max==0) {
1466: $deg_of_disc = 'nan';
1467: } else {
1468: $deg_of_disc = ($top_sum/$top_max) - ($bottom_sum/$bottom_max);
1469: }
1470: #&Apache::lonnet::logthis(' '.$top_sum.'/'.$top_max.
1471: # ' - '.$bottom_sum.'/'.$bottom_max);
1472: return $deg_of_disc;
1473: }
1474:
1475: ###############################################
1476: ###############################################
1477: ##
1478: ## Compute KR-21
1479: ##
1480: ## To compute KR-21, you need the following information:
1481: ##
1482: ## K=the number of items in your test
1483: ## M=the mean score on the test
1484: ## s=the standard deviation of the scores on your test
1485: ##
1486: ## then:
1487: ##
1488: ## KR-21 rk= [K/(K-1)] * [1- (M*(K-M))/(K*s^2))]
1489: ##
1490: ###############################################
1491: ###############################################
1492: sub compute_sequence_statistics {
1493: my ($seq) = @_;
1494: my $symb = $seq->{'symb'};
1495: my @Resources;
1496: foreach my $res (@{$seq->{'contents'}}) {
1497: next if ($res->{'type'} ne 'assessment');
1498: push (@Resources,$res->{'symb'});
1499: }
1500: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
1501: #
1502: # First compute statistics based on student scores
1503: my ($smin,$smax,$sMean,$sSTD,$scount,$sMAX) =
1504: &Apache::loncoursedata::score_stats
1505: (\@Apache::lonstatistics::SelectedSections,
1506: $Apache::lonstatistics::enrollment_status,
1507: \@Resources,$starttime,$endtime,undef);
1508: $SeqStat{$symb}->{'title'} = $seq->{'title'};
1509: $SeqStat{$symb}->{'scoremax'} = $smax;
1510: $SeqStat{$symb}->{'scoremin'} = $smin;
1511: $SeqStat{$symb}->{'scoremean'} = $sMean;
1512: $SeqStat{$symb}->{'scorestd'} = $sSTD;
1513: $SeqStat{$symb}->{'scorecount'} = $scount;
1514: $SeqStat{$symb}->{'max_possible'} = $sMAX;
1515: #
1516: # Compute statistics based on the number of correct problems
1517: # 'correct' is taken to mean
1518: my ($cmin,$cmax,$cMean,$cSTD,$ccount)=
1519: &Apache::loncoursedata::count_stats
1520: (\@Apache::lonstatistics::SelectedSections,
1521: $Apache::lonstatistics::enrollment_status,
1522: \@Resources,$starttime,$endtime,undef);
1523: my $K = $seq->{'num_assess_parts'};
1524: my $kr_21;
1525: if ($K > 1 && $cSTD > 0) {
1526: $kr_21 = ($K/($K-1)) * (1 - $cMean*($K-$cMean)/($K*$cSTD**2));
1527: } else {
1528: $kr_21 = 'nan';
1529: }
1530: $SeqStat{$symb}->{'countmax'} = $cmax;
1531: $SeqStat{$symb}->{'countmin'} = $cmin;
1532: $SeqStat{$symb}->{'countstd'} = $cSTD;
1533: $SeqStat{$symb}->{'count'} = $ccount;
1534: $SeqStat{$symb}->{'items'} = $K;
1535: $SeqStat{$symb}->{'KR-21'}=$kr_21;
1536:
1537: return;
1538: }
1539:
1540:
1541:
1542: =pod
1543:
1544: =item ProblemStatisticsLegend
1545:
1546: =over 4
1547:
1548: =item #Stdnts
1549: Total number of students attempted the problem.
1550:
1551: =item Tries
1552: Total number of tries for solving the problem.
1553:
1554: =item Max Tries
1555: Largest number of tries for solving the problem by a student.
1556:
1557: =item Mean
1558: Average number of tries. [ Tries / #Stdnts ]
1559:
1560: =item #YES
1561: Number of students solved the problem correctly.
1562:
1563: =item #yes
1564: Number of students solved the problem by override.
1565:
1566: =item %Wrong
1567: Percentage of students who tried to solve the problem
1568: but is still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]
1569:
1570: =item DoDiff
1571: Degree of Difficulty of the problem.
1572: [ 1 - ((#YES+#yes) / Tries) ]
1573:
1574: =item S.D.
1575: Standard Deviation of the tries.
1576: [ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1)
1577: where Xi denotes every student\'s tries ]
1578:
1579: =item Skew.
1580: Skewness of the students tries.
1581: [(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]
1582:
1583: =item Dis.F.
1584: Discrimination Factor: A Standard for evaluating the
1585: problem according to a Criterion<br>
1586:
1587: =item [Criterion to group students into %27 Upper Students -
1588: and %27 Lower Students]
1589: 1st Criterion for Sorting the Students:
1590: Sum of Partial Credit Awarded / Total Number of Tries
1591: 2nd Criterion for Sorting the Students:
1592: Total number of Correct Answers / Total Number of Tries
1593:
1594: =item Disc.
1595: Number of Students had at least one discussion.
1596:
1597: =back
1598:
1599: =cut
1600:
1601: ############################################################
1602: ############################################################
1603:
1604: 1;
1605: __END__
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