File:
[LON-CAPA] /
loncom /
interface /
statistics /
lonproblemstatistics.pm
Revision
1.79:
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Thu Apr 1 20:02:56 2004 UTC (20 years, 3 months ago) by
matthew
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MAIN
CVS tags:
HEAD
Bug 539: Report KR-21 reliability statistic
loncoursedata.pm:
Added &limit_by_start_end_time to consolidate $starttime and $endtime code.
Added &score_stats and &count_stats to return summary data on the scores
and problem correct counts.
lonproblemstatistics:
Added description of @Fields data structures
Added @SeqFields, &output_sequence_statistics, &sequence_html_header,
&sequence_html_output, and &compute_sequence_statistics.
Reporting statistics on sequences (instead of problems) is still being
fleshed out, interface wise. No Excel output is available for sequence
statistics at this time.
1: # The LearningOnline Network with CAPA
2: #
3: # $Id: lonproblemstatistics.pm,v 1.79 2004/04/01 20:02:56 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: selected => 'yes',
105: },
106: { name => 'container',
107: title => 'Sequence or Folder',
108: align => 'left',
109: color => '#FFFFE6',
110: sortable => 'yes',
111: selectable => 'no',
112: selected => 'yes',
113: },
114: { name => 'title',
115: title => 'Title',
116: align => 'left',
117: color => '#FFFFE6',
118: special => 'link',
119: sortable => 'yes',
120: selectable => 'no',
121: selected => 'yes',
122: },
123: { name => 'part',
124: title => 'Part',
125: align => 'left',
126: color => '#FFFFE6',
127: selectable => 'no',
128: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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: selected => '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 ($field->{'selected'} eq 'yes') {
419: push(@{$ENV{'form.fieldselections'}},$field->{'name'});
420: }
421: }
422: }
423: #
424: # This should not happen, but in case it does...
425: if (ref($ENV{'form.fieldselections'}) ne 'ARRAY') {
426: $ENV{'form.fieldselections'} = [$ENV{'form.fieldselections'}];
427: }
428: #
429: # Set the field data and the selected fields (for easier checking)
430: undef(%SelectedFields);
431: foreach my $field (@Fields) {
432: next if ($field->{'selectable'} ne 'yes');
433: $field->{'selected'} = 'no';
434: foreach my $selection (@{$ENV{'form.fieldselections'}}) {
435: if ($selection eq $field->{'name'} || $selection eq 'all') {
436: $field->{'selected'} = 'yes';
437: $SelectedFields{$field->{'name'}}++;
438: }
439: }
440: }
441: return;
442: }
443:
444: sub field_selection_input {
445: my $Str = '<select name="fieldselections" multiple size="5">'."\n";
446: $Str .= '<option value="all">all</option>'."\n";
447: foreach my $field (@Fields) {
448: next if ($field->{'selectable'} ne 'yes');
449: $Str .= ' <option value="'.$field->{'name'}.'" ';
450: if ($field->{'selected'} eq 'yes') {
451: $Str .= 'selected ';
452: }
453: $Str .= '>'.$field->{'title'}.'</option>'."\n";
454: }
455: $Str .= "</select>\n";
456: }
457:
458: ###############################################
459: ###############################################
460:
461: =pod
462:
463: =item &CreateInterface()
464:
465: Create the main intereface for the statistics page. Allows the user to
466: select sections, maps, and output.
467:
468: =cut
469:
470: ###############################################
471: ###############################################
472: sub CreateInterface {
473: &parse_field_selection();
474: my $Str = '';
475: $Str .= &Apache::lonhtmlcommon::breadcrumbs
476: (undef,'Overall Problem Statistics','Statistics_Overall_Key');
477: $Str .= '<table cellspacing="5">'."\n";
478: $Str .= '<tr>';
479: $Str .= '<td align="center"><b>'.&mt('Sections').'</b></td>';
480: $Str .= '<td align="center"><b>'.&mt('Enrollment Status').'</b></td>';
481: $Str .= '<td align="center"><b>'.&mt('Sequences and Folders').'</b></td>';
482: $Str .= '<td align="center"><b>'.&mt('Statistics').'</b></td>';
483: $Str .= '<td rowspan="2">'.
484: &Apache::lonstathelpers::limit_by_time_form().'</td>';
485: $Str .= '</tr>'."\n";
486: #
487: $Str .= '<tr><td align="center">'."\n";
488: $Str .= &Apache::lonstatistics::SectionSelect('Section','multiple',5);
489: $Str .= '</td><td align="center">';
490: $Str .= &Apache::lonhtmlcommon::StatusOptions(undef,undef,5);
491: $Str .= '</td><td align="center">';
492: #
493: my $only_seq_with_assessments = sub {
494: my $s=shift;
495: if ($s->{'num_assess'} < 1) {
496: return 0;
497: } else {
498: return 1;
499: }
500: };
501: $Str .= &Apache::lonstatistics::MapSelect('Maps','multiple,all',5,
502: $only_seq_with_assessments);
503: $Str .= '</td><td>'.&field_selection_input();
504: $Str .= '</td></tr>'."\n";
505: $Str .= '</table>'."\n";
506: $Str .= '<input type="submit" name="GenerateStatistics" value="'.
507: &mt('Generate Statistics').'" />';
508: $Str .= ' 'x5;
509: $Str .= 'Plot '.&plot_dropdown().(' 'x10);
510: $Str .= '<input type="submit" name="ClearCache" value="'.
511: &mt('Clear Caches').'" />';
512: $Str .= ' 'x5;
513: $Str .= '<input type="submit" name="UpdateCache" value="'.
514: &mt('Update Student Data').'" />';
515: $Str .= ' 'x5;
516: $Str .= '<input type="submit" name="Excel" value="'.
517: &mt('Produce Excel Output').'" />';
518: $Str .= ' 'x5;
519: return $Str;
520: }
521:
522: ###############################################
523: ###############################################
524:
525: =pod
526:
527: =item &BuildProblemStatisticsPage()
528:
529: Main interface to problem statistics.
530:
531: =cut
532:
533: ###############################################
534: ###############################################
535: sub BuildProblemStatisticsPage {
536: my ($r,$c)=@_;
537: #
538: my %Saveable_Parameters = ('Status' => 'scalar',
539: 'statsoutputmode' => 'scalar',
540: 'Section' => 'array',
541: 'StudentData' => 'array',
542: 'Maps' => 'array',
543: 'fieldselections'=> 'array');
544: &Apache::loncommon::store_course_settings('statistics',
545: \%Saveable_Parameters);
546: &Apache::loncommon::restore_course_settings('statistics',
547: \%Saveable_Parameters);
548: #
549: &Apache::lonstatistics::PrepareClasslist();
550: #
551: # Clear the package variables
552: undef(@StatsArray);
553: undef(%SeqStat);
554: #
555: # Finally let the user know we are here
556: my $interface = &CreateInterface();
557: $r->print($interface);
558: $r->print('<input type="hidden" name="sortby" value="'.$ENV{'form.sortby'}.
559: '" />');
560: #
561: if (! exists($ENV{'form.statsfirstcall'})) {
562: $r->print('<input type="hidden" name="statsfirstcall" value="yes" />');
563: $r->print('<h3>'.
564: &mt('Press "Generate Statistics" when you are ready.').
565: '</h3><p>'.
566: &mt('It may take some time to update the student data '.
567: 'for the first analysis. Future analysis this session '.
568: ' will not have this delay.').
569: '</p>');
570: return;
571: } elsif ($ENV{'form.statsfirstcall'} eq 'yes' ||
572: exists($ENV{'form.UpdateCache'}) ||
573: exists($ENV{'form.ClearCache'}) ) {
574: $r->print('<input type="hidden" name="statsfirstcall" value="no" />');
575: &Apache::lonstatistics::Gather_Student_Data($r);
576: } else {
577: $r->print('<input type="hidden" name="statsfirstcall" value="no" />');
578: }
579: $r->rflush();
580: #
581: # This probably does not need to be done each time we are called, but
582: # it does not slow things down noticably.
583: &Apache::loncoursedata::populate_weight_table();
584: #
585: if (exists($ENV{'form.Excel'})) {
586: &Excel_output($r);
587: } else {
588: my $count = 0;
589: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
590: $count += $seq->{'num_assess_parts'};
591: }
592: if ($count > 10) {
593: $r->print('<h2>'.
594: &mt('Compiling statistics for [_1] problems',$count).
595: '</h2>');
596: if ($count > 30) {
597: $r->print('<h3>'.&mt('This will take some time.').'</h3>');
598: }
599: $r->rflush();
600: }
601: #
602: my $sortby = $ENV{'form.sortby'};
603: $sortby = 'container' if (! defined($sortby) || $sortby =~ /^\s*$/);
604: my $plot = $ENV{'form.plot'};
605: if ($plot eq '' || $plot eq 'none') {
606: undef($plot);
607: }
608: if ($sortby eq 'container' && ! defined($plot)) {
609: &output_sequence_statistics($r);
610: &output_html_by_sequence($r);
611: } else {
612: if (defined($plot)) {
613: &make_plot($r,$plot);
614: }
615: &output_html_stats($r);
616: &output_sequence_statistics($r);
617: }
618: }
619: return;
620: }
621:
622: sub output_sequence_statistics {
623: my ($r) = @_;
624: my $c=$r->connection();
625: $r->print('<h2>'.&mt('Sequence Statistics').'</h2>');
626: $r->print('<table border="0"><tr><td bgcolor="#777777">'."\n".
627: '<table border="0" cellpadding="3">'."\n".
628: '<tr bgcolor="#FFFFE6">');
629: $r->print(&sequence_html_header());
630: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
631: last if ($c->aborted);
632: next if ($seq->{'num_assess'} < 1);
633: &compute_sequence_statistics($seq);
634: $r->print(&sequence_html_output($seq));
635: }
636: $r->print('</table>');
637: $r->print('</table>');
638: $r->rflush();
639: return;
640: }
641:
642:
643: ##########################################################
644: ##########################################################
645: ##
646: ## HTML output routines
647: ##
648: ##########################################################
649: ##########################################################
650: sub output_html_by_sequence {
651: my ($r) = @_;
652: my $c = $r->connection();
653: $r->print(&html_preamble());
654: #
655: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
656: last if ($c->aborted);
657: next if ($seq->{'num_assess'} < 1);
658: $r->print("<h3>".$seq->{'title'}."</h3>".
659: '<table border="0"><tr><td bgcolor="#777777">'."\n".
660: '<table border="0" cellpadding="3">'."\n".
661: '<tr bgcolor="#FFFFE6">'.
662: &statistics_table_header('no container')."</tr>\n");
663: my @Data = &compute_statistics_on_sequence($seq);
664: foreach my $data (@Data) {
665: $r->print('<tr>'.&statistics_html_table_data($data,
666: 'no container').
667: "</tr>\n");
668: }
669: $r->print('</table>'."\n".'</table>'."\n");
670: $r->rflush();
671: }
672: return;
673: }
674:
675: sub output_html_stats {
676: my ($r)=@_;
677: &compute_all_statistics($r);
678: $r->print(&html_preamble());
679: &sort_data($ENV{'form.sortby'});
680: #
681: my $count=0;
682: foreach my $data (@StatsArray) {
683: if ($count++ % 50 == 0) {
684: $r->print("</table>\n</table>\n");
685: $r->print('<table border="0"><tr><td bgcolor="#777777">'."\n".
686: '<table border="0" cellpadding="3">'."\n".
687: '<tr bgcolor="#FFFFE6">'.
688: '<tr bgcolor="#FFFFE6">'.
689: &statistics_table_header().
690: "</tr>\n");
691: }
692: $r->print('<tr>'.&statistics_html_table_data($data)."</tr>\n");
693: }
694: $r->print("</table>\n</table>\n");
695: return;
696: }
697:
698: sub html_preamble {
699: my $Str='';
700: $Str .= "<h2>".
701: $ENV{'course.'.$ENV{'request.course.id'}.'.description'}.
702: "</h2>\n";
703: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
704: if (defined($starttime) || defined($endtime)) {
705: # Inform the user what the time limits on the data are.
706: $Str .= '<h3>'.&mt('Statistics on submissions from [_1] to [_2]',
707: &Apache::lonlocal::locallocaltime($starttime),
708: &Apache::lonlocal::locallocaltime($endtime)
709: ).'</h3>';
710: }
711: $Str .= "<h3>".&mt('Compiled on [_1]',
712: &Apache::lonlocal::locallocaltime(time))."</h3>";
713: return $Str;
714: }
715:
716:
717: ###############################################
718: ###############################################
719: ##
720: ## Misc HTML output routines
721: ##
722: ###############################################
723: ###############################################
724: sub statistics_html_table_data {
725: my ($data,$options) = @_;
726: my $row = '';
727: foreach my $field (@Fields) {
728: next if ($options =~ /no $field->{'name'}/);
729: next if ($field->{'selected'} ne 'yes');
730: $row .= '<td bgcolor="'.$field->{'color'}.'"';
731: if (exists($field->{'align'})) {
732: $row .= ' align="'.$field->{'align'}.'"';
733: }
734: $row .= '>';
735: if (exists($field->{'special'}) && $field->{'special'} eq 'link') {
736: $row .= '<a href="'.$data->{$field->{'name'}.'.link'}.'">';
737: }
738: if (exists($field->{'format'})) {
739: $row .= sprintf($field->{'format'},$data->{$field->{'name'}});
740: } else {
741: $row .= $data->{$field->{'name'}};
742: }
743: if (exists($field->{'special'}) && $field->{'special'} eq 'link') {
744: $row.= '</a>';
745: }
746: $row .= '</td>';
747: }
748: return $row;
749: }
750:
751: sub statistics_table_header {
752: my ($options) = @_;
753: my $header_row;
754: foreach my $field (@Fields) {
755: next if ($options =~ /no $field->{'name'}/);
756: next if ($field->{'selected'} ne 'yes');
757: $header_row .= '<th>';
758: if (exists($field->{'sortable'}) && $field->{'sortable'} eq 'yes') {
759: $header_row .= '<a href="javascript:'.
760: 'document.Statistics.sortby.value='."'".$field->{'name'}."'".
761: ';document.Statistics.submit();">';
762: }
763: $header_row .= &mt($field->{'title'});
764: if ($options =~ /sortable/) {
765: $header_row.= '</a>';
766: }
767: if ($options !~ /no plots/ &&
768: exists($field->{'graphable'}) &&
769: $field->{'graphable'} eq 'yes') {
770: $header_row.=' (';
771: $header_row .= '<a href="javascript:'.
772: "document.Statistics.plot.value='$field->{'name'}'".
773: ';document.Statistics.submit();">';
774: $header_row .= &mt('plot').'</a>)';
775: }
776: $header_row .= '</th>';
777: }
778: return $header_row;
779: }
780:
781: sub sequence_html_header {
782: my $Str .= '<tr>';
783: foreach my $field (@SeqFields) {
784: # next if ($field->{'selected'} ne 'yes');
785: $Str .= '<th bgcolor="'.$field->{'color'}.'"';
786: $Str .= '>'.$field->{'title'}.'</th>';
787: }
788: $Str .= '</tr>';
789: return $Str;
790: }
791:
792:
793: sub sequence_html_output {
794: my ($seq) = @_;
795: my $data = $SeqStat{$seq->{'symb'}};
796: # $SeqStat{$symb}->{'max'}
797: # $SeqStat{$symb}->{'min'}
798: # $SeqStat{$symb}->{'mean'}
799: # $SeqStat{$symb}->{'std'}
800: # $SeqStat{$symb}->{'count'}
801: # $SeqStat{$symb}->{'max_possible'}
802: my $row = '<tr>';
803: foreach my $field (@SeqFields) {
804: # next if ($field->{'selected'} ne 'yes');
805: $row .= '<td bgcolor="'.$field->{'color'}.'"';
806: if (exists($field->{'align'})) {
807: $row .= ' align="'.$field->{'align'}.'"';
808: }
809: $row .= '>';
810: if (exists($field->{'format'})) {
811: $row .= sprintf($field->{'format'},$data->{$field->{'name'}});
812: } else {
813: $row .= $data->{$field->{'name'}};
814: }
815: $row .= '</td>';
816: }
817: $row .= '</tr>'."\n";
818: return $row;
819: }
820:
821: ####################################################
822: ####################################################
823: ##
824: ## Plotting Routines
825: ##
826: ####################################################
827: ####################################################
828: sub make_plot {
829: my ($r,$plot) = @_;
830: &compute_all_statistics($r);
831: &sort_data($ENV{'form.sortby'});
832: if ($plot eq 'degrees') {
833: °rees_plot($r);
834: } elsif ($plot eq 'tries statistics') {
835: &tries_data_plot($r);
836: } else {
837: &make_single_stat_plot($r,$plot);
838: }
839: return;
840: }
841:
842: sub make_single_stat_plot {
843: my ($r,$datafield) = @_;
844: #
845: my $title; my $yaxis;
846: foreach my $field (@Fields) {
847: next if ($field->{'name'} ne $datafield);
848: $title = $field->{'long_title'};
849: $yaxis = $field->{'title'};
850: last;
851: }
852: if ($title eq '' || $yaxis eq '') {
853: # datafield is something we do not know enough about to plot
854: $r->print('<h3>'.
855: &mt('Unable to plot the requested statistic.').
856: '</h3>');
857: return;
858: }
859: #
860: # Build up the data sets to plot
861: my @Labels;
862: my @Data;
863: my $max = 1;
864: foreach my $data (@StatsArray) {
865: push(@Labels,$data->{'problem_num'});
866: push(@Data,$data->{$datafield});
867: if ($data->{$datafield}>$max) {
868: $max = $data->{$datafield};
869: }
870: }
871: foreach (1,2,3,4,5,10,15,20,25,40,50,75,100,150,200,250,300,500,600,750,
872: 1000,1500,2000,2500,3000,3500,4000,5000,7500,10000,15000,20000) {
873: if ($max <= $_) {
874: $max = $_;
875: last;
876: }
877: }
878: if ($max > 20000) {
879: $max = 10000*(int($max/10000)+1);
880: }
881: #
882: $r->print("<p>".&Apache::loncommon::DrawBarGraph($title,
883: 'Problem Number',
884: $yaxis,
885: $max,
886: undef, # colors
887: \@Labels,
888: \@Data)."</p>\n");
889: return;
890: }
891:
892: sub degrees_plot {
893: my ($r)=@_;
894: my $count = scalar(@StatsArray);
895: my $width = 50 + 10*$count;
896: $width = 300 if ($width < 300);
897: my $height = 300;
898: my $plot = '';
899: my $ymax = 0;
900: my $ymin = 0;
901: my @Disc; my @Diff; my @Labels;
902: foreach my $data (@StatsArray) {
903: push(@Labels,$data->{'problem_num'});
904: my $disc = $data->{'deg_of_disc'};
905: my $diff = $data->{'deg_of_diff'};
906: push(@Disc,$disc);
907: push(@Diff,$diff);
908: #
909: $ymin = $disc if ($ymin > $disc);
910: $ymin = $diff if ($ymin > $diff);
911: $ymax = $disc if ($ymax < $disc);
912: $ymax = $diff if ($ymax < $diff);
913: }
914: #
915: # Make sure we show relevant information.
916: if ($ymin < 0) {
917: if (abs($ymin) < 0.05) {
918: $ymin = 0;
919: } else {
920: $ymin = -1;
921: }
922: }
923: if ($ymax > 0) {
924: if (abs($ymax) < 0.05) {
925: $ymax = 0;
926: } else {
927: $ymax = 1;
928: }
929: }
930: #
931: my $xmax = $Labels[-1];
932: if ($xmax > 50) {
933: if ($xmax % 10 != 0) {
934: $xmax = 10 * (int($xmax/10)+1);
935: }
936: } else {
937: if ($xmax % 5 != 0) {
938: $xmax = 5 * (int($xmax/5)+1);
939: }
940: }
941: #
942: my $discdata .= '<data>'.join(',',@Labels).'</data>'.$/.
943: '<data>'.join(',',@Disc).'</data>'.$/;
944: #
945: my $diffdata .= '<data>'.join(',',@Labels).'</data>'.$/.
946: '<data>'.join(',',@Diff).'</data>'.$/;
947: #
948: $plot=<<"END";
949: <gnuplot
950: texfont="10"
951: fgcolor="x000000"
952: plottype="Cartesian"
953: font="large"
954: grid="on"
955: align="center"
956: border="on"
957: transparent="on"
958: alttag="Sample Plot"
959: samples="100"
960: bgcolor="xffffff"
961: height="$height"
962: width="$width">
963: <key
964: pos="top right"
965: title=""
966: box="off" />
967: <title>Degree of Discrmination and Degree of Difficulty</title>
968: <axis xmin="0" ymin="$ymin" xmax="$xmax" ymax="$ymax" color="x000000" />
969: <xlabel>Problem Number</xlabel>
970: <curve
971: linestyle="linespoints"
972: name="DoDisc"
973: pointtype="0"
974: color="x000000">
975: $discdata
976: </curve>
977: <curve
978: linestyle="linespoints"
979: name="DoDiff"
980: pointtype="0"
981: color="xFF0000">
982: $diffdata
983: </curve>
984: </gnuplot>
985: END
986: my $plotresult =
987: '<p>'.&Apache::lonxml::xmlparse($r,'web',$plot).'</p>'.$/;
988: $r->print($plotresult);
989: return;
990: }
991:
992: sub tries_data_plot {
993: my ($r)=@_;
994: my $count = scalar(@StatsArray);
995: my $width = 50 + 10*$count;
996: $width = 300 if ($width < 300);
997: my $height = 300;
998: my $plot = '';
999: my @STD; my @Mean; my @Max; my @Min;
1000: my @Labels;
1001: my $ymax = 5;
1002: foreach my $data (@StatsArray) {
1003: my $max = $data->{'mean_tries'} + $data->{'std_tries'};
1004: $ymax = $max if ($ymax < $max);
1005: $ymax = $max if ($ymax < $max);
1006: push(@Labels,$data->{'problem_num'});
1007: push(@STD,$data->{'std_tries'});
1008: push(@Mean,$data->{'mean_tries'});
1009: }
1010: #
1011: # Make sure we show relevant information.
1012: my $xmax = $Labels[-1];
1013: if ($xmax > 50) {
1014: if ($xmax % 10 != 0) {
1015: $xmax = 10 * (int($xmax/10)+1);
1016: }
1017: } else {
1018: if ($xmax % 5 != 0) {
1019: $xmax = 5 * (int($xmax/5)+1);
1020: }
1021: }
1022: $ymax = int($ymax)+1+2;
1023: #
1024: my $std_data .= '<data>'.join(',',@Labels).'</data>'.$/.
1025: '<data>'.join(',',@Mean).'</data>'.$/;
1026: #
1027: my $std_error_data .= '<data>'.join(',',@Labels).'</data>'.$/.
1028: '<data>'.join(',',@Mean).'</data>'.$/.
1029: '<data>'.join(',',@STD).'</data>'.$/;
1030: #
1031: $plot=<<"END";
1032: <gnuplot
1033: texfont="10"
1034: fgcolor="x000000"
1035: plottype="Cartesian"
1036: font="large"
1037: grid="on"
1038: align="center"
1039: border="on"
1040: transparent="on"
1041: alttag="Sample Plot"
1042: samples="100"
1043: bgcolor="xffffff"
1044: height="$height"
1045: width="$width">
1046: <title>Mean and S.D. of Tries</title>
1047: <axis xmin="0" ymin="0" xmax="$xmax" ymax="$ymax" color="x000000" />
1048: <xlabel>Problem Number</xlabel>
1049: <curve
1050: linestyle="yerrorbars"
1051: name="S.D. Tries"
1052: pointtype="1"
1053: color="x666666">
1054: $std_error_data
1055: </curve>
1056: <curve
1057: linestyle="points"
1058: name="Mean Tries"
1059: pointtype="1"
1060: color="xCC4444">
1061: $std_data
1062: </curve>
1063: </gnuplot>
1064: END
1065: my $plotresult =
1066: '<p>'.&Apache::lonxml::xmlparse($r,'web',$plot).'</p>'.$/;
1067: $r->print($plotresult);
1068: return;
1069: }
1070:
1071: sub plot_dropdown {
1072: my $current = '';
1073: #
1074: if (defined($ENV{'form.plot'})) {
1075: $current = $ENV{'form.plot'};
1076: }
1077: #
1078: my @Additional_Plots = (
1079: { graphable=>'yes',
1080: name => 'degrees',
1081: title => 'DoDisc and DoDiff' },
1082: { graphable=>'yes',
1083: name => 'tries statistics',
1084: title => 'Mean and S.D. of Tries' });
1085: #
1086: my $Str= "\n".'<select name="plot" size="1">';
1087: $Str .= '<option name="none"></option>'."\n";
1088: $Str .= '<option name="none2">none</option>'."\n";
1089: foreach my $field (@Fields,@Additional_Plots) {
1090: if (! exists($field->{'graphable'}) ||
1091: $field->{'graphable'} ne 'yes') {
1092: next;
1093: }
1094: $Str .= '<option value="'.$field->{'name'}.'"';
1095: if ($field->{'name'} eq $current) {
1096: $Str .= ' selected ';
1097: }
1098: $Str.= '>'.&mt($field->{'title'}).'</option>'."\n";
1099: }
1100: $Str .= '</select>'."\n";
1101: return $Str;
1102: }
1103:
1104: ###############################################
1105: ###############################################
1106: ##
1107: ## Excel output routines
1108: ##
1109: ###############################################
1110: ###############################################
1111: sub Excel_output {
1112: my ($r) = @_;
1113: $r->print('<h2>'.&mt('Preparing Excel Spreadsheet').'</h2>');
1114: ##
1115: ## Compute the statistics
1116: &compute_all_statistics($r);
1117: my $c = $r->connection;
1118: return if ($c->aborted());
1119: ##
1120: ## Create the excel workbook
1121: my $filename = '/prtspool/'.
1122: $ENV{'user.name'}.'_'.$ENV{'user.domain'}.'_'.
1123: time.'_'.rand(1000000000).'.xls';
1124: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
1125: #
1126: # Create sheet
1127: my $excel_workbook = Spreadsheet::WriteExcel->new('/home/httpd'.$filename);
1128: #
1129: # Check for errors
1130: if (! defined($excel_workbook)) {
1131: $r->log_error("Error creating excel spreadsheet $filename: $!");
1132: $r->print(&mt("Problems creating new Excel file. ".
1133: "This error has been logged. ".
1134: "Please alert your LON-CAPA administrator."));
1135: return 0;
1136: }
1137: #
1138: # The excel spreadsheet stores temporary data in files, then put them
1139: # together. If needed we should be able to disable this (memory only).
1140: # The temporary directory must be specified before calling 'addworksheet'.
1141: # File::Temp is used to determine the temporary directory.
1142: $excel_workbook->set_tempdir($Apache::lonnet::tmpdir);
1143: #
1144: # Add a worksheet
1145: my $sheetname = $ENV{'course.'.$ENV{'request.course.id'}.'.description'};
1146: if (length($sheetname) > 31) {
1147: $sheetname = substr($sheetname,0,31);
1148: }
1149: my $excel_sheet = $excel_workbook->addworksheet(
1150: &Apache::loncommon::clean_excel_name($sheetname));
1151: ##
1152: ## Begin creating excel sheet
1153: ##
1154: my ($rows_output,$cols_output) = (0,0);
1155: #
1156: # Put the course description in the header
1157: $excel_sheet->write($rows_output,$cols_output++,
1158: $ENV{'course.'.$ENV{'request.course.id'}.'.description'});
1159: $cols_output += 3;
1160: #
1161: # Put a description of the sections listed
1162: my $sectionstring = '';
1163: my @Sections = @Apache::lonstatistics::SelectedSections;
1164: if (scalar(@Sections) > 1) {
1165: if (scalar(@Sections) > 2) {
1166: my $last = pop(@Sections);
1167: $sectionstring = "Sections ".join(', ',@Sections).', and '.$last;
1168: } else {
1169: $sectionstring = "Sections ".join(' and ',@Sections);
1170: }
1171: } else {
1172: if ($Sections[0] eq 'all') {
1173: $sectionstring = "All sections";
1174: } else {
1175: $sectionstring = "Section ".$Sections[0];
1176: }
1177: }
1178: $excel_sheet->write($rows_output,$cols_output++,$sectionstring);
1179: $cols_output += scalar(@Sections);
1180: #
1181: # Time restrictions
1182: my $time_string;
1183: if (defined($starttime)) {
1184: # call localtime but not lonlocal:locallocaltime because excel probably
1185: # cannot handle localized text. Probably.
1186: $time_string .= 'Data collected from '.localtime($time_string);
1187: if (defined($endtime)) {
1188: $time_string .= ' to '.localtime($endtime);
1189: }
1190: $time_string .= '.';
1191: } elsif (defined($endtime)) {
1192: # See note above about lonlocal:locallocaltime
1193: $time_string .= 'Data collected before '.localtime($endtime).'.';
1194: }
1195: #
1196: # Put the date in there too
1197: $excel_sheet->write($rows_output,$cols_output++,
1198: 'Compiled on '.localtime(time));
1199: #
1200: $rows_output++;
1201: $cols_output=0;
1202: #
1203: # Long Headers
1204: foreach my $field (@Fields) {
1205: next if ($field->{'name'} eq 'problem_num');
1206: next if ($field->{'selected'} ne 'yes');
1207: if (exists($field->{'long_title'})) {
1208: $excel_sheet->write($rows_output,$cols_output++,
1209: $field->{'long_title'});
1210: } else {
1211: $excel_sheet->write($rows_output,$cols_output++,'');
1212: }
1213: }
1214: $rows_output++;
1215: $cols_output=0;
1216: # Brief headers
1217: foreach my $field (@Fields) {
1218: next if ($field->{'selected'} ne 'yes');
1219: next if ($field->{'name'} eq 'problem_num');
1220: # Use english for excel as I am not sure how well excel handles
1221: # other character sets....
1222: $excel_sheet->write($rows_output,$cols_output++,$field->{'title'});
1223: }
1224: $rows_output++;
1225: foreach my $data (@StatsArray) {
1226: $cols_output=0;
1227: foreach my $field (@Fields) {
1228: next if ($field->{'selected'} ne 'yes');
1229: next if ($field->{'name'} eq 'problem_num');
1230: $excel_sheet->write($rows_output,$cols_output++,
1231: $data->{$field->{'name'}});
1232: }
1233: $rows_output++;
1234: }
1235: #
1236: $excel_workbook->close();
1237: #
1238: # Tell the user where to get their excel file
1239: $r->print('<br />'.
1240: '<a href="'.$filename.'">'.
1241: &mt('Your Excel Spreadsheet').'</a>'."\n");
1242: $r->rflush();
1243: return;
1244: }
1245:
1246: ##################################################
1247: ##################################################
1248: ##
1249: ## Statistics Gathering and Manipulation Routines
1250: ##
1251: ##################################################
1252: ##################################################
1253: sub compute_statistics_on_sequence {
1254: my ($seq) = @_;
1255: my @Data;
1256: foreach my $res (@{$seq->{'contents'}}) {
1257: next if ($res->{'type'} ne 'assessment');
1258: foreach my $part (@{$res->{'parts'}}) {
1259: #
1260: # This is where all the work happens
1261: my $data = &get_statistics($seq,$res,$part,scalar(@StatsArray)+1);
1262: push (@Data,$data);
1263: push (@StatsArray,$data);
1264: }
1265: }
1266: return @Data;
1267: }
1268:
1269: sub compute_all_statistics {
1270: my ($r) = @_;
1271: if (@StatsArray > 0) {
1272: # Assume we have already computed the statistics
1273: return;
1274: }
1275: my $c = $r->connection;
1276: foreach my $seq (&Apache::lonstatistics::Sequences_with_Assess()) {
1277: last if ($c->aborted);
1278: next if ($seq->{'num_assess'} < 1);
1279: &compute_statistics_on_sequence($seq);
1280: }
1281: }
1282:
1283: sub sort_data {
1284: my ($sortkey) = @_;
1285: return if (! @StatsArray);
1286: #
1287: # Sort the data
1288: my $sortby = undef;
1289: foreach my $field (@Fields) {
1290: if ($sortkey eq $field->{'name'}) {
1291: $sortby = $field->{'name'};
1292: }
1293: }
1294: if (! defined($sortby) || $sortby eq '' || $sortby eq 'problem_num') {
1295: $sortby = 'container';
1296: }
1297: if ($sortby ne 'container') {
1298: # $sortby is already defined, so we can charge ahead
1299: if ($sortby =~ /^(title|part)$/i) {
1300: # Alpha comparison
1301: @StatsArray = sort {
1302: lc($a->{$sortby}) cmp lc($b->{$sortby}) ||
1303: lc($a->{'title'}) cmp lc($b->{'title'}) ||
1304: lc($a->{'part'}) cmp lc($b->{'part'});
1305: } @StatsArray;
1306: } else {
1307: # Numerical comparison
1308: @StatsArray = sort {
1309: my $retvalue = 0;
1310: if ($b->{$sortby} eq 'nan') {
1311: if ($a->{$sortby} ne 'nan') {
1312: $retvalue = -1;
1313: } else {
1314: $retvalue = 0;
1315: }
1316: }
1317: if ($a->{$sortby} eq 'nan') {
1318: if ($b->{$sortby} ne 'nan') {
1319: $retvalue = 1;
1320: }
1321: }
1322: if ($retvalue eq '0') {
1323: $retvalue = $b->{$sortby} <=> $a->{$sortby} ||
1324: lc($a->{'title'}) <=> lc($b->{'title'}) ||
1325: lc($a->{'part'}) <=> lc($b->{'part'});
1326: }
1327: $retvalue;
1328: } @StatsArray;
1329: }
1330: }
1331: #
1332: # Renumber the data set
1333: my $count;
1334: foreach my $data (@StatsArray) {
1335: $data->{'problem_num'} = ++$count;
1336: }
1337: return;
1338: }
1339:
1340: ########################################################
1341: ########################################################
1342:
1343: =pod
1344:
1345: =item &get_statistics()
1346:
1347: Wrapper routine from the call to loncoursedata::get_problem_statistics.
1348: Calls lonstathelpers::get_time_limits() to limit the data set by time
1349: and &compute_discrimination_factor
1350:
1351: Inputs: $sequence, $resource, $part, $problem_num
1352:
1353: Returns: Hash reference with statistics data from
1354: loncoursedata::get_problem_statistics.
1355:
1356: =cut
1357:
1358: ########################################################
1359: ########################################################
1360: sub get_statistics {
1361: my ($sequence,$resource,$part,$problem_num) = @_;
1362: #
1363: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
1364: my $symb = $resource->{'symb'};
1365: my $courseid = $ENV{'request.course.id'};
1366: #
1367: my $data = &Apache::loncoursedata::get_problem_statistics
1368: (\@Apache::lonstatistics::SelectedSections,
1369: $Apache::lonstatistics::enrollment_status,
1370: $symb,$part,$courseid,$starttime,$endtime);
1371: $data->{'part'} = $part;
1372: $data->{'problem_num'} = $problem_num;
1373: $data->{'container'} = $sequence->{'title'};
1374: $data->{'title'} = $resource->{'title'};
1375: $data->{'title.link'} = $resource->{'src'}.'?symb='.
1376: &Apache::lonnet::escape($resource->{'symb'});
1377: #
1378: if ($SelectedFields{'deg_of_disc'}) {
1379: $data->{'deg_of_disc'} =
1380: &compute_discrimination_factor($resource,$part,$sequence);
1381: }
1382: return $data;
1383: }
1384:
1385: ###############################################
1386: ###############################################
1387:
1388: =pod
1389:
1390: =item &compute_discrimination_factor()
1391:
1392: Inputs: $Resource, $Sequence
1393:
1394: Returns: integer between -1 and 1
1395:
1396: =cut
1397:
1398: ###############################################
1399: ###############################################
1400: sub compute_discrimination_factor {
1401: my ($resource,$part,$sequence) = @_;
1402: my @Resources;
1403: foreach my $res (@{$sequence->{'contents'}}) {
1404: next if ($res->{'symb'} eq $resource->{'symb'});
1405: push (@Resources,$res->{'symb'});
1406: }
1407: #
1408: # rank
1409: my $ranking =
1410: &Apache::loncoursedata::rank_students_by_scores_on_resources
1411: (\@Resources,
1412: \@Apache::lonstatistics::SelectedSections,
1413: $Apache::lonstatistics::enrollment_status,undef);
1414: #
1415: # compute their percent scores on the problems in the sequence,
1416: my $number_to_grab = int(scalar(@{$ranking})/4);
1417: my $num_students = scalar(@{$ranking});
1418: my @BottomSet = map { $_->[&Apache::loncoursedata::RNK_student()];
1419: } @{$ranking}[0..$number_to_grab];
1420: my @TopSet =
1421: map {
1422: $_->[&Apache::loncoursedata::RNK_student()];
1423: } @{$ranking}[($num_students-$number_to_grab)..($num_students-1)];
1424: my ($bottom_sum,$bottom_max) =
1425: &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@BottomSet);
1426: my ($top_sum,$top_max) =
1427: &Apache::loncoursedata::get_sum_of_scores($resource,$part,\@TopSet);
1428: my $deg_of_disc;
1429: if ($top_max == 0 || $bottom_max==0) {
1430: $deg_of_disc = 'nan';
1431: } else {
1432: $deg_of_disc = ($top_sum/$top_max) - ($bottom_sum/$bottom_max);
1433: }
1434: #&Apache::lonnet::logthis(' '.$top_sum.'/'.$top_max.
1435: # ' - '.$bottom_sum.'/'.$bottom_max);
1436: return $deg_of_disc;
1437: }
1438:
1439: ###############################################
1440: ###############################################
1441: ##
1442: ## Compute KR-21
1443: ##
1444: ## To compute KR-21, you need the following information:
1445: ##
1446: ## K=the number of items in your test
1447: ## M=the mean score on the test
1448: ## s=the standard deviation of the scores on your test
1449: ##
1450: ## then:
1451: ##
1452: ## KR-21 rk= [K/(K-1)] * [1- (M*(K-M))/(K*s^2))]
1453: ##
1454: ###############################################
1455: ###############################################
1456: sub compute_sequence_statistics {
1457: my ($seq) = @_;
1458: my $symb = $seq->{'symb'};
1459: my @Resources;
1460: foreach my $res (@{$seq->{'contents'}}) {
1461: next if ($res->{'type'} ne 'assessment');
1462: push (@Resources,$res->{'symb'});
1463: }
1464: my ($starttime,$endtime) = &Apache::lonstathelpers::get_time_limits();
1465: #
1466: # First compute statistics based on student scores
1467: my ($smin,$smax,$sMean,$sSTD,$scount,$sMAX) =
1468: &Apache::loncoursedata::score_stats
1469: (\@Apache::lonstatistics::SelectedSections,
1470: $Apache::lonstatistics::enrollment_status,
1471: \@Resources,$starttime,$endtime,undef);
1472: $SeqStat{$symb}->{'title'} = $seq->{'title'};
1473: $SeqStat{$symb}->{'scoremax'} = $smax;
1474: $SeqStat{$symb}->{'scoremin'} = $smin;
1475: $SeqStat{$symb}->{'scoremean'} = $sMean;
1476: $SeqStat{$symb}->{'scorestd'} = $sSTD;
1477: $SeqStat{$symb}->{'scorecount'} = $scount;
1478: $SeqStat{$symb}->{'max_possible'} = $sMAX;
1479: #
1480: # Compute statistics based on the number of correct problems
1481: # 'correct' is taken to mean
1482: my ($cmin,$cmax,$cMean,$cSTD,$ccount)=
1483: &Apache::loncoursedata::count_stats
1484: (\@Apache::lonstatistics::SelectedSections,
1485: $Apache::lonstatistics::enrollment_status,
1486: \@Resources,$starttime,$endtime,undef);
1487: my $K = $seq->{'num_assess_parts'};
1488: my $kr_21;
1489: if ($K > 1 && $cSTD > 0) {
1490: $kr_21 = ($K/($K-1)) * (1 - $cMean*($K-$cMean)/($K*$cSTD**2));
1491: } else {
1492: $kr_21 = 'nan';
1493: }
1494: $SeqStat{$symb}->{'countmax'} = $cmax;
1495: $SeqStat{$symb}->{'countmin'} = $cmin;
1496: $SeqStat{$symb}->{'countstd'} = $cSTD;
1497: $SeqStat{$symb}->{'count'} = $ccount;
1498: $SeqStat{$symb}->{'items'} = $K;
1499: $SeqStat{$symb}->{'KR-21'}=$kr_21;
1500:
1501: return;
1502: }
1503:
1504:
1505:
1506: =pod
1507:
1508: =item ProblemStatisticsLegend
1509:
1510: =over 4
1511:
1512: =item #Stdnts
1513: Total number of students attempted the problem.
1514:
1515: =item Tries
1516: Total number of tries for solving the problem.
1517:
1518: =item Max Tries
1519: Largest number of tries for solving the problem by a student.
1520:
1521: =item Mean
1522: Average number of tries. [ Tries / #Stdnts ]
1523:
1524: =item #YES
1525: Number of students solved the problem correctly.
1526:
1527: =item #yes
1528: Number of students solved the problem by override.
1529:
1530: =item %Wrong
1531: Percentage of students who tried to solve the problem
1532: but is still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]
1533:
1534: =item DoDiff
1535: Degree of Difficulty of the problem.
1536: [ 1 - ((#YES+#yes) / Tries) ]
1537:
1538: =item S.D.
1539: Standard Deviation of the tries.
1540: [ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1)
1541: where Xi denotes every student\'s tries ]
1542:
1543: =item Skew.
1544: Skewness of the students tries.
1545: [(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]
1546:
1547: =item Dis.F.
1548: Discrimination Factor: A Standard for evaluating the
1549: problem according to a Criterion<br>
1550:
1551: =item [Criterion to group students into %27 Upper Students -
1552: and %27 Lower Students]
1553: 1st Criterion for Sorting the Students:
1554: Sum of Partial Credit Awarded / Total Number of Tries
1555: 2nd Criterion for Sorting the Students:
1556: Total number of Correct Answers / Total Number of Tries
1557:
1558: =item Disc.
1559: Number of Students had at least one discussion.
1560:
1561: =back
1562:
1563: =cut
1564:
1565: ############################################################
1566: ############################################################
1567:
1568: 1;
1569: __END__
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