-
Notifications
You must be signed in to change notification settings - Fork 7
/
Copy pathdiscovery_static_forPDF.html
8025 lines (7283 loc) · 399 KB
/
discovery_static_forPDF.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html><html lang="en" dir="ltr"><head><meta http-equiv="content-type" content="text/html; charset=utf-8"><meta name="generator" content="ReSpec 24.4.5"><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"><style>/* --- EXAMPLES --- */
span.example-title {
text-transform: none;
}
aside.example, div.example, div.illegal-example {
padding: 0.5em;
margin: 1em 0;
position: relative;
clear: both;
}
div.illegal-example { color: red }
div.illegal-example p { color: black }
aside.example, div.example {
padding: .5em;
border-left-width: .5em;
border-left-style: solid;
border-color: #e0cb52;
background: #fcfaee;
}
aside.example div.example {
border-left-width: .1em;
border-color: #999;
background: #fff;
}
aside.example div.example span.example-title {
color: #999;
}
</style><style>/* --- ISSUES/NOTES --- */
.issue-label {
text-transform: initial;
}
.warning > p:first-child { margin-top: 0 }
.warning {
padding: .5em;
border-left-width: .5em;
border-left-style: solid;
}
span.warning { padding: .1em .5em .15em; }
.issue.closed span.issue-number {
text-decoration: line-through;
}
.warning {
border-color: #f11;
border-width: .2em;
border-style: solid;
background: #fbe9e9;
}
.warning-title:before{
content: "⚠"; /*U+26A0 WARNING SIGN*/
font-size: 3em;
float: left;
height: 100%;
padding-right: .3em;
vertical-align: top;
margin-top: -0.5em;
}
li.task-list-item {
list-style: none;
}
input.task-list-item-checkbox {
margin: 0 0.35em 0.25em -1.6em;
vertical-align: middle;
}
.issue a.respec-gh-label {
padding: 5px;
margin: 0 2px 0 2px;
font-size: 10px;
text-transform: none;
text-decoration: none;
font-weight: bold;
border-radius: 4px;
position: relative;
bottom: 2px;
border: none;
}
.issue a.respec-label-dark {
color: #fff;
background-color: #000;
}
.issue a.respec-label-light {
color: #000;
background-color: #fff;
}
</style>
<title>DDI-RDF Discovery Vocabulary</title>
<style type="text/css">
table { border: black 1px solid; border-collapse:collapse; border-spacing: 0; }
table td { border: black 1px solid; padding: 3px; padding-left: 10px; padding-right: 10px; text-align: center; vertical-align: top;}
.classDefinitions dd{margin-left: 25px;}
.classProperties{margin-left:25px;margin-bottom: 15px;margin-top:15px;}
.classProperties dt{margin-top: 15px;}
.figcaption {
margin-top: 0.75em;
}
@media screen
{
.screen-hidden {
display: none;
}
#combined-uml-diagram-object-properties-only {
width: 88%;
}
}
@media print
{
img {
width: 95%;
}
#combined-uml-diagram-object-properties-only {
width: 88%;
}
.print-hidden {
display: none;
}
.table {
width: 100%;
}
/*
IE: OK
Firefox: 11.3.3 "Data Sets, Data Files, and Descriptive Statistics" too wide.
*/
}
</style>
<script type="text/javascript">
//<![CDATA[
// Adjustment of size of UML diagrams to 55% of original size or if wider than the screen to 90% of screen width.
// UML diagrams must have the CSS class "uml-diagram" (no additional classes).
var maxWidth = screen.width*0.9;
var scaleFactor = 0.55;
function adjustWidthOfImages() {
var images = document.getElementsByTagName( 'img' );
for ( var i=0; i<images.length; i++ ) {
var image = images[i];
if ( image.className.toLowerCase() == 'uml-diagram' ) { // works only if this single CSS class name exists
var imageWidth = Math.round( image.naturalWidth * scaleFactor );
if ( imageWidth > maxWidth ) {
elementWidth = maxWidth;
} else {
elementWidth = imageWidth;
}
image.style.width = ( elementWidth ).toString() + 'px';
}
}
}
//]]></script>
<style id="respec-mainstyle">/*****************************************************************
* ReSpec 3 CSS
* Robin Berjon - http://berjon.com/
*****************************************************************/
/* Override code highlighter background */
.hljs {
background: transparent !important;
}
/* --- INLINES --- */
h1 abbr,
h2 abbr,
h3 abbr,
h4 abbr,
h5 abbr,
h6 abbr,
a abbr {
border: none;
}
dfn {
font-weight: bold;
}
a.internalDFN {
color: inherit;
border-bottom: 1px solid #99c;
text-decoration: none;
}
a.externalDFN {
color: inherit;
border-bottom: 1px dotted #ccc;
text-decoration: none;
}
a.bibref {
text-decoration: none;
}
#references :target {
background: #eaf3ff;
}
cite .bibref {
font-style: normal;
}
code {
color: #c83500;
}
th code {
color: inherit;
}
/* --- TOC --- */
.toc a,
.tof a {
text-decoration: none;
}
a .secno,
a .figno {
color: #000;
}
ul.tof,
ol.tof {
list-style: none outside none;
}
.caption {
margin-top: 0.5em;
font-style: italic;
}
/* --- TABLE --- */
table.simple {
border-spacing: 0;
border-collapse: collapse;
border-bottom: 3px solid #005a9c;
}
.simple th {
background: #005a9c;
color: #fff;
padding: 3px 5px;
text-align: left;
}
.simple th[scope="row"] {
background: inherit;
color: inherit;
border-top: 1px solid #ddd;
}
.simple td {
padding: 3px 10px;
border-top: 1px solid #ddd;
}
.simple tr:nth-child(even) {
background: #f0f6ff;
}
/* --- DL --- */
.section dd>p:first-child {
margin-top: 0;
}
.section dd>p:last-child {
margin-bottom: 0;
}
.section dd {
margin-bottom: 1em;
}
.section dl.attrs dd,
.section dl.eldef dd {
margin-bottom: 0;
}
#issue-summary>ul,
.respec-dfn-list {
column-count: 2;
}
#issue-summary li,
.respec-dfn-list li {
list-style: none;
}
details.respec-tests-details {
margin-left: 1em;
display: inline-block;
vertical-align: top;
}
details.respec-tests-details>* {
padding-right: 2em;
}
details.respec-tests-details[open] {
z-index: 999999;
position: absolute;
border: thin solid #cad3e2;
border-radius: 0.3em;
background-color: white;
padding-bottom: 0.5em;
}
details.respec-tests-details[open]>summary {
border-bottom: thin solid #cad3e2;
padding-left: 1em;
margin-bottom: 1em;
line-height: 2em;
}
details.respec-tests-details>ul {
width: 100%;
margin-top: -0.3em;
}
details.respec-tests-details>li {
padding-left: 1em;
}
a[href].self-link:hover {
opacity: 1;
text-decoration: none;
background-color: transparent;
}
h2,
h3,
h4,
h5,
h6 {
position: relative;
}
aside.example .marker > a.self-link {
color: inherit;
}
h2>a.self-link,
h3>a.self-link,
h4>a.self-link,
h5>a.self-link,
h6>a.self-link {
border: none;
color: inherit;
font-size: 83%;
height: 2em;
left: -1.6em;
opacity: .5;
position: absolute;
text-align: center;
text-decoration: none;
top: 0;
transition: opacity .2s;
width: 2em;
}
h2>a.self-link::before,
h3>a.self-link::before,
h4>a.self-link::before,
h5>a.self-link::before,
h6>a.self-link::before {
content: "§";
display: block;
}
@media (max-width: 767px) {
dd {
margin-left: 0;
}
/* Don't position self-link in headings off-screen */
h2>a.self-link,
h3>a.self-link,
h4>a.self-link,
h5>a.self-link,
h6>a.self-link {
left: auto;
top: auto;
}
}
@media print {
.removeOnSave {
display: none;
}
}
</style>
<link rel="canonical" href="https://www.w3.org/TR/Disco/"><style>/*
github.com style (c) Vasily Polovnyov <[email protected]>
*/
.hljs {
display: block;
overflow-x: auto;
padding: 0.5em;
color: #333;
background: #f8f8f8;
}
.hljs-comment,
.hljs-quote {
color: #998;
font-style: italic;
}
.hljs-keyword,
.hljs-selector-tag,
.hljs-subst {
color: #333;
font-weight: bold;
}
.hljs-number,
.hljs-literal,
.hljs-variable,
.hljs-template-variable,
.hljs-tag .hljs-attr {
color: #008080;
}
.hljs-string,
.hljs-doctag {
color: #d14;
}
.hljs-title,
.hljs-section,
.hljs-selector-id {
color: #900;
font-weight: bold;
}
.hljs-subst {
font-weight: normal;
}
.hljs-type,
.hljs-class .hljs-title {
color: #458;
font-weight: bold;
}
.hljs-tag,
.hljs-name,
.hljs-attribute {
color: #000080;
font-weight: normal;
}
.hljs-regexp,
.hljs-link {
color: #009926;
}
.hljs-symbol,
.hljs-bullet {
color: #990073;
}
.hljs-built_in,
.hljs-builtin-name {
color: #0086b3;
}
.hljs-meta {
color: #999;
font-weight: bold;
}
.hljs-deletion {
background: #fdd;
}
.hljs-addition {
background: #dfd;
}
.hljs-emphasis {
font-style: italic;
}
.hljs-strong {
font-weight: bold;
}
</style><script id="initialUserConfig" type="application/json">{
"specStatus": "base",
"shortName": "Disco",
"subtitle": "A vocabulary for publishing metadata about data sets (research and survey data) into the Web of Linked Data",
"copyrightStart": "2019",
"editors": [
{
"name": "Thomas Hartmann (formerly Bosch)",
"url": "http://www.dr-thomashartmann.de/"
},
{
"name": "Richard Cyganiak",
"url": "https://www.linkedin.com/in/cygri",
"company": "TopQuadrant",
"companyURL": "http://www.topquadrant.com/"
},
{
"name": "Joachim Wackerow",
"url": "https://www.gesis.org/institut/mitarbeiterverzeichnis/person/?tx_gextstaffdir_staffdirectory%5bemail%[email protected]",
"company": "GESIS - Leibniz Institute for the Social Sciences, Germany",
"companyURL": "http://www.gesis.org/"
},
{
"name": "Benjamin Zapilko",
"url": "https://www.gesis.org/institut/mitarbeiterverzeichnis/person/?tx_gextstaffdir_staffdirectory%5bemail%[email protected]",
"company": "GESIS - Leibniz Institute for the Social Sciences, Germany",
"companyURL": "http://www.gesis.org/"
}
],
"authors": [
{
"name": "Thomas Hartmann (formerly Bosch)",
"url": "http://www.dr-thomashartmann.de/"
},
{
"name": "Sarven Capadisli",
"url": "http://csarven.ca/",
"company": "Enterprise Information Systems (EIS)",
"companyURL": "http://eis.iai.uni-bonn.de/"
},
{
"name": "Franck Cotton",
"company": "INSEE - Institut National de la Statistique et des Études Économiques, France",
"companyURL": "http://www.insee.fr/en/default.asp"
},
{
"name": "Richard Cyganiak",
"url": "https://www.linkedin.com/in/cygri",
"company": "TopQuadrant",
"companyURL": "http://www.topquadrant.com/"
},
{
"name": "Arofan Gregory",
"company": "ODaF - Open Data Foundation, USA",
"companyURL": "http://www.opendatafoundation.org/"
},
{
"name": "Benedikt Kämpgen",
"url": "http://www.aifb.kit.edu/web/Benedikt_K%C3%A4mpgen/en",
"company": "Institute of Applied Informatics and Formal Description Methods (AIFB), Germany",
"companyURL": "http://www.aifb.kit.edu/web/Hauptseite/en"
},
{
"name": "Olof Olsson",
"url": "https://www.gu.se/english/about_the_university/staff/?languageId=100001&userId=xoolof&departmentId=169030",
"company": "SND - Swedish National Data Service",
"companyURL": "http://snd.gu.se/en"
},
{
"name": "Heiko Paulheim",
"url": "http://www.heikopaulheim.com/",
"company": "Data and Web Science Group, University of Mannheim, Germany",
"companyURL": "http://dws.informatik.uni-mannheim.de/"
},
{
"name": "Joachim Wackerow",
"url": "http://www.gesis.org/en/institute/staff/?alpha=W&name=joachim%2Cwackerow",
"company": "GESIS - Leibniz Institute for the Social Sciences, Germany",
"companyURL": "http://www.gesis.org/"
},
{
"name": "Benjamin Zapilko",
"url": "http://www.gesis.org/en/institute/staff/?alpha=Z&name=benjamin%2Czapilko",
"company": "GESIS - Leibniz Institute for the Social Sciences, Germany",
"companyURL": "http://www.gesis.org/"
}
],
"alternateFormats": [
{
"uri": "DDI-RDF_Discovery_Vocabulary.pdf",
"label": "PDF"
}
],
"doRDFa": false,
"wg": "DDI Alliance RDF Vocabularies Working Group",
"wgURI": "http://www.ddialliance.org/community/working-groups",
"wgPublicList": "[email protected]",
"wgPatentURI": "http://creativecommons.org/licenses/by/4.0/",
"maxTocLevel": "2",
"publishISODate": "2019-03-14T00:00:00.000Z",
"generatedSubtitle": "Document 14 March 2019"
}</script><link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/2016/base.css"></head>
<body onload="adjustWidthOfImages()" class="h-entry informative"><div class="head">
<h1 id="title" class="title p-name">DDI-RDF Discovery Vocabulary</h1>
<h2 id="subtitle" class="subtitle">A vocabulary for publishing metadata about data sets (research and survey data) into the Web of Linked Data</h2>
<dl>
<dt>Editors:</dt>
<dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://www.dr-thomashartmann.de/">Thomas Hartmann (formerly Bosch)</a></dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="https://www.linkedin.com/in/cygri">Richard Cyganiak</a>
(<a class="p-org org h-org h-card" href="http://www.topquadrant.com/">TopQuadrant</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="https://www.gesis.org/institut/mitarbeiterverzeichnis/person/?tx_gextstaffdir_staffdirectory%5bemail%[email protected]">Joachim Wackerow</a>
(<a class="p-org org h-org h-card" href="http://www.gesis.org/">GESIS - Leibniz Institute for the Social Sciences, Germany</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="https://www.gesis.org/institut/mitarbeiterverzeichnis/person/?tx_gextstaffdir_staffdirectory%5bemail%[email protected]">Benjamin Zapilko</a>
(<a class="p-org org h-org h-card" href="http://www.gesis.org/">GESIS - Leibniz Institute for the Social Sciences, Germany</a>)
</dd>
<dt>
Authors:
</dt><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://www.dr-thomashartmann.de/">Thomas Hartmann (formerly Bosch)</a></dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://csarven.ca/">Sarven Capadisli</a>
(<a class="p-org org h-org h-card" href="http://eis.iai.uni-bonn.de/">Enterprise Information Systems (EIS)</a>)
</dd><dd class="p-author h-card vcard"><span class="p-name fn">Franck Cotton</span>
(<a class="p-org org h-org h-card" href="http://www.insee.fr/en/default.asp">INSEE - Institut National de la Statistique et des Études Économiques, France</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="https://www.linkedin.com/in/cygri">Richard Cyganiak</a>
(<a class="p-org org h-org h-card" href="http://www.topquadrant.com/">TopQuadrant</a>)
</dd><dd class="p-author h-card vcard"><span class="p-name fn">Arofan Gregory</span>
(<a class="p-org org h-org h-card" href="http://www.opendatafoundation.org/">ODaF - Open Data Foundation, USA</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://www.aifb.kit.edu/web/Benedikt_K%C3%A4mpgen/en">Benedikt Kämpgen</a>
(<a class="p-org org h-org h-card" href="http://www.aifb.kit.edu/web/Hauptseite/en">Institute of Applied Informatics and Formal Description Methods (AIFB), Germany</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="https://www.gu.se/english/about_the_university/staff/?languageId=100001&userId=xoolof&departmentId=169030">Olof Olsson</a>
(<a class="p-org org h-org h-card" href="http://snd.gu.se/en">SND - Swedish National Data Service</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://www.heikopaulheim.com/">Heiko Paulheim</a>
(<a class="p-org org h-org h-card" href="http://dws.informatik.uni-mannheim.de/">Data and Web Science Group, University of Mannheim, Germany</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://www.gesis.org/en/institute/staff/?alpha=W&name=joachim%2Cwackerow">Joachim Wackerow</a>
(<a class="p-org org h-org h-card" href="http://www.gesis.org/">GESIS - Leibniz Institute for the Social Sciences, Germany</a>)
</dd><dd class="p-author h-card vcard"><a class="u-url url p-name fn" href="http://www.gesis.org/en/institute/staff/?alpha=Z&name=benjamin%2Czapilko">Benjamin Zapilko</a>
(<a class="p-org org h-org h-card" href="http://www.gesis.org/">GESIS - Leibniz Institute for the Social Sciences, Germany</a>)
</dd>
</dl>
<p>
This document is also available in this non-normative format:
<a rel="alternate" href="DDI-RDF_Discovery_Vocabulary.pdf">PDF</a>
</p>
<p class="copyright">
Copyright © 2019 <a href="http://www.ddialliance.org/">DDI Alliance</a>
</p>
<hr title="Separator for header">
</div>
<section id="abstract" class="introductory"><h2>Abstract</h2>
This specification defines the DDI-RDF Discovery Vocabulary (Disco), an RDF Schema vocabulary that enables discovery of research and survey data on the Web. It is based on <a href="http://www.ddialliance.org/what">DDI (Data Documentation Initiative)</a> XML formats.
</section>
<section id="sotd" class="introductory"><h2>Status of This Document</h2>
<p>
The DDI-RDF Discovery Vocabulary is a draft specification of the DDI Alliance.
</p>
<p>This specification is produced by the subgroup on Disco (chair Joachim Wackerow) of the
<a href="http://www.ddialliance.org/alliance/working-groups#RDF">RDF Vocabularies Working Group</a>,
a working group at the <a href="http://www.ddialliance.org/alliance">DDI Alliance</a>.</p>
<p>Resources:</p>
<ul>
<li><a href="http://www.ddialliance.org/Specification/RDF/Discovery">Webpage at DDI Alliance</a></li>
<li><a href="https://groups.google.com/group/ddi-rdf-vocabulary">Google Group</a></li>
<li><a href="https://github.com/linked-statistics/disco-spec/issues">Issue tracker</a></li>
<li><a href="https://github.com/linked-statistics/disco-spec/">GitHub repository</a></li>
</ul>
</section><nav id="toc"><h2 class="introductory" id="table-of-contents">Table of Contents</h2><ol class="toc"><li class="tocline"><a class="tocxref" href="#tof"><span class="secno">1. </span>Table of Figures</a></li><li class="tocline"><a class="tocxref" href="#introduction"><span class="secno">2. </span>Introduction</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#scope-and-purpose"><span class="secno">2.1 </span>Scope and Purpose</a></li><li class="tocline"><a class="tocxref" href="#about-ddi"><span class="secno">2.2 </span>About DDI</a></li><li class="tocline"><a class="tocxref" href="#relationship-to-data-cube-dcat-and-xkos"><span class="secno">2.3 </span>Relationship to Data Cube, DCAT and XKOS</a></li></ol></li><li class="tocline"><a class="tocxref" href="#overview"><span class="secno">3. </span>Overview</a></li><li class="tocline"><a class="tocxref" href="#example"><span class="secno">4. </span>Real-life Example</a></li><li class="tocline"><a class="tocxref" href="#study"><span class="secno">5. </span>Studies and StudyGroups</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#coverage-references-to-ddi-xml-files-and-kind-of-data"><span class="secno">5.1 </span>Coverage, References to DDI-XML Files, and Kind of Data</a></li><li class="tocline"><a class="tocxref" href="#relationships-to-agents"><span class="secno">5.2 </span>Relationships to Agents</a></li><li class="tocline"><a class="tocxref" href="#analysis-units-and-universes"><span class="secno">5.3 </span>Analysis Units and Universes</a></li></ol></li><li class="tocline"><a class="tocxref" href="#metadata"><span class="secno">6. </span>General Metadata</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#identification"><span class="secno">6.1 </span>Identification</a></li><li class="tocline"><a class="tocxref" href="#versioning-information"><span class="secno">6.2 </span>Versioning Information</a></li><li class="tocline"><a class="tocxref" href="#links-to-related-files"><span class="secno">6.3 </span>Links to Related Files</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#access-rights-statements-and-licenses"><span class="secno">6.4 </span>Access Rights Statements and Licenses</a></li><li class="tocline"><a class="tocxref" href="#coverage-of-studies-logical-datasets-and-data-files"><span class="secno">6.5 </span>Coverage of Studies, Logical Datasets, and Data Files</a></li><li class="tocline"><a class="tocxref" href="#other-general-dublin-core-metadata-properties"><span class="secno">6.6 </span>Other General Dublin Core Metadata Properties</a></li></ol></li><li class="tocline"><a class="tocxref" href="#dataset"><span class="secno">7. </span>Data Sets, Data Files, and Descriptive Statistics</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#logicaldataset"><span class="secno">7.1 </span>LogicalDataSet</a></li><li class="tocline"><a class="tocxref" href="#datafile"><span class="secno">7.2 </span>DataFile</a></li><li class="tocline"><a class="tocxref" href="#descriptivestatistics"><span class="secno">7.3 </span>DescriptiveStatistics</a></li></ol></li><li class="tocline"><a class="tocxref" href="#variable"><span class="secno">8. </span>Variables, Variable Definitions, Representations, and Concepts</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#variable-and-variable-definition"><span class="secno">8.1 </span>Variable and Variable Definition</a></li><li class="tocline"><a class="tocxref" href="#representation"><span class="secno">8.2 </span>Representation</a></li><li class="tocline"><a class="tocxref" href="#codes-and-categories"><span class="secno">8.3 </span>Codes and Categories</a></li><li class="tocline"><a class="tocxref" href="#ordering"><span class="secno">8.4 </span>Ordering</a></li></ol></li><li class="tocline"><a class="tocxref" href="#collection"><span class="secno">9. </span>Data Collection</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#instrument"><span class="secno">9.1 </span>Instrument</a></li><li class="tocline"><a class="tocxref" href="#question"><span class="secno">9.2 </span>Question</a></li></ol></li><li class="tocline"><a class="tocxref" href="#useOfOtherVocabularies"><span class="secno">10. </span>Use of Other Vocabularies</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#dcmi-metadata-terms-dcmi"><span class="secno">10.1 </span>DCMI Metadata Terms (DCMI)</a></li><li class="tocline"><a class="tocxref" href="#simple-knowledge-organization-system-skos"><span class="secno">10.2 </span>Simple Knowledge Organization System (SKOS)</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#data-catalog-vocabulary-dcat"><span class="secno">10.3 </span>Data Catalog Vocabulary (DCAT)</a></li><li class="tocline"><a class="tocxref" href="#friend-of-a-friend-foaf-and-organization-ontology-org"><span class="secno">10.4 </span>Friend of a Friend (FOAF) and Organization Ontology (ORG)</a></li><li class="tocline"><a class="tocxref" href="#adms"><span class="secno">10.5 </span>Asset Description Metadata Schema (ADMS)</a></li><li class="tocline"><a class="tocxref" href="#prov-ontology-prov-o"><span class="secno">10.6 </span>PROV Ontology (PROV-O)</a></li><li class="tocline"><a class="tocxref" href="#rdf-data-cube-vocabulary-qb"><span class="secno">10.7 </span>RDF Data Cube Vocabulary (QB)</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#skos-extension-for-statistics-xkos"><span class="secno">10.8 </span>SKOS Extension for Statistics (XKOS)</a></li><li class="tocline"><a class="tocxref" href="#semanticscience-integrated-ontology-sio"><span class="secno">10.9 </span>Semanticscience Integrated Ontology (SIO)</a></li></ol></li><li class="tocline"><a class="tocxref" href="#mapping-from-DDI-XML-to-DDI-RDF"><span class="secno">11. </span>DDI-XML Bidirectional Mappings</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#representation-of-mappings-in-rdf"><span class="secno">11.1 </span>Representation of Mappings in RDF</a></li><li class="tocline"><a class="tocxref" href="#classes"><span class="secno">11.2 </span>Classes</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#object-properties"><span class="secno">11.3 </span>Object Properties</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#data-properties"><span class="secno">11.4 </span>Data Properties</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#overview-of-the-mapping-from-ddi-c-and-ddi-l-to-ddi-rdf"><span class="secno">11.5 </span>Overview of the Mapping from DDI-C and DDI-L to DDI-RDF</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#mapping-from-ddi-c-to-ddi-rdf"><span class="secno">11.6 </span>Mapping from DDI-C to DDI-RDF</a><ol class="toc"></ol></li><li class="tocline"><a class="tocxref" href="#mapping-from-ddi-l-to-ddi-rdf"><span class="secno">11.7 </span>Mapping from DDI-L to DDI-RDF</a><ol class="toc"></ol></li></ol></li><li class="tocline"><a class="tocxref" href="#mappings"><span class="secno">12. </span>Mappings to other Models</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#gsim"><span class="secno">12.1 </span>GSIM</a></li><li class="tocline"><a class="tocxref" href="#schema-org"><span class="secno">12.2 </span>Schema.org</a></li></ol></li><li class="tocline"><a class="tocxref" href="#implementations"><span class="secno">13. </span>Reference Implementations</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#microdata-information-system-missy"><span class="secno">13.1 </span>Microdata Information System (MISSY)</a><ol class="toc"></ol></li></ol></li><li class="tocline"><a class="tocxref" href="#vocabulary-reference"><span class="secno">A. </span>Vocabulary Reference</a></li><li class="tocline"><a class="tocxref" href="#combined-uml-diagram"><span class="secno">B. </span>Combined UML Diagram</a></li><li class="tocline"><a class="tocxref" href="#use-cases-and-example-queries"><span class="secno">C. </span>Use Cases and Example Queries</a></li><li class="tocline"><a class="tocxref" href="#acknowledgements"><span class="secno">D. </span>Acknowledgements</a></li><li class="tocline"><a class="tocxref" href="#references"><span class="secno">E. </span>References</a><ol class="toc"><li class="tocline"><a class="tocxref" href="#normative-references"><span class="secno">E.1 </span>Normative references</a></li><li class="tocline"><a class="tocxref" href="#informative-references"><span class="secno">E.2 </span>Informative references</a></li></ol></li></ol></nav>
<section id="tof">
<!-- placeholder for generated table of diagrams -->
<!--OddPage--><h2 id="x1-table-of-figures"><span class="secno">1. </span>Table of Figures<a class="self-link" aria-label="§" href="#tof"></a></h2><ul class="tof"><li class="tofline">
<a class="tocxref" href="#fig-vocabulary-overview">Figure <span class="figno">1</span> <span class="fig-title">Vocabulary Overview</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-overview">Figure <span class="figno">2</span> <span class="fig-title">Overview</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-coverage-and-universe">Figure <span class="figno">3</span> <span class="fig-title">Coverage and Universe</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-access-policy">Figure <span class="figno">4</span> <span class="fig-title">Access Policy</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-questionnaires">Figure <span class="figno">5</span> <span class="fig-title">Questionnaires</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-variables-list">Figure <span class="figno">6</span> <span class="fig-title">Variables List</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-variable-details">Figure <span class="figno">7</span> <span class="fig-title">Variable Details</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-concept-variable-link">Figure <span class="figno">8</span> <span class="fig-title">Concept-Variable Link</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-general-data-set-information">Figure <span class="figno">9</span> <span class="fig-title">General Data Set Information</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-coverage-references-to-ddi-xml-files-and-kind-of-data">Figure <span class="figno">10</span> <span class="fig-title">Coverage, References to DDI-XML Files, and Kind of Data</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-relationships-to-agents">Figure <span class="figno">11</span> <span class="fig-title">Relationships to Agents</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-study-universe-and-analysisunit">Figure <span class="figno">12</span> <span class="fig-title">Study, Universe and AnalysisUnit</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-identification">Figure <span class="figno">13</span> <span class="fig-title">Identification</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-versioning-information">Figure <span class="figno">14</span> <span class="fig-title">Versioning Information</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-links-to-related-files">Figure <span class="figno">15</span> <span class="fig-title">Links to Related Files</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-access-rights-statements-and-licenses">Figure <span class="figno">16</span> <span class="fig-title">Access Rights Statements and Licenses</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-study-coverage">Figure <span class="figno">17</span> <span class="fig-title">Study Coverage</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-logicaldataset-coverage">Figure <span class="figno">18</span> <span class="fig-title">LogicalDataSet Coverage</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-datafile-coverage">Figure <span class="figno">19</span> <span class="fig-title">DataFile Coverage</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-overview-data-sets-data-files-descriptive-statistics">Figure <span class="figno">20</span> <span class="fig-title">Overview: Data Sets, Data Files, Descriptive Statistics</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-logicaldataset">Figure <span class="figno">21</span> <span class="fig-title">LogicalDataSet</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-datafile">Figure <span class="figno">22</span> <span class="fig-title">DataFile</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-descriptivestatistics">Figure <span class="figno">23</span> <span class="fig-title">DescriptiveStatistics</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-example-category-statistics-frequency-table-of-variable-partliv-issp-2011">Figure <span class="figno">24</span> <span class="fig-title">Example Category Statistics: Frequency Table of Variable PARTLIV (ISSP 2011)</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-example-category-statistics-frequency-table-of-variable-wrkhrs-issp-2011">Figure <span class="figno">25</span> <span class="fig-title">Example Category Statistics: Frequency Table of Variable WRKHRS (ISSP 2011)</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-example-summary-statistics-descriptive-statistics-of-variable-wrkhrs-issp-2011">Figure <span class="figno">26</span> <span class="fig-title">Example Summary Statistics: Descriptive Statistics of Variable WRKHRS (ISSP 2011)</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-summary-statistics">Figure <span class="figno">27</span> <span class="fig-title">Summary Statistics</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-category-statistics">Figure <span class="figno">28</span> <span class="fig-title">Category Statistics</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-variables-variable-definitions-representations-and-concepts">Figure <span class="figno">29</span> <span class="fig-title">Variables, Variable Definitions, Representations, and Concepts</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-variables-and-representedvariables">Figure <span class="figno">30</span> <span class="fig-title">Variables and RepresentedVariables</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-representation">Figure <span class="figno">31</span> <span class="fig-title">Representation</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-skos-concept-and-skos-conceptscheme">Figure <span class="figno">32</span> <span class="fig-title">skos:Concept and skos:ConceptScheme</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-example-category-statistics-frequency-table-of-variable-partliv-issp-2011-0">Figure <span class="figno">33</span> <span class="fig-title">Example Category Statistics: Frequency Table of Variable PARTLIV (ISSP 2011)</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-example-category-statistics-frequency-table-of-variable-partliv-issp-2011-1">Figure <span class="figno">34</span> <span class="fig-title">Example Category Statistics: Frequency Table of Variable PARTLIV (ISSP 2011)</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-datacollection">Figure <span class="figno">35</span> <span class="fig-title">DataCollection</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-representation-of-mappings-in-rdf">Figure <span class="figno">36</span> <span class="fig-title">Representation of Mappings in RDF</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-combined-uml-diagram-object-properties-only">Figure <span class="figno">37</span> <span class="fig-title">Combined UML Diagram (object properties only)</span></a>
</li><li class="tofline">
<a class="tocxref" href="#fig-statistical-classification-anzsic">Figure <span class="figno">38</span> <span class="fig-title">Statistical classification – ANZSIC</span></a>
</li></ul></section>
<section id="introduction">
<!--OddPage--><h2 id="x2-introduction"><span class="secno">2. </span>Introduction<a class="self-link" aria-label="§" href="#introduction"></a></h2>
<p>
The namespace for all terms in this ontology is: http://rdf-vocabulary.ddialliance.org/discovery#".
</p>
<p>
Normative formats of the DDI-RDF Discovery Vocabulary specification are
</p><ul>
<li>this HTML specification, and </li>
<li>the <a href="https://raw.github.com/linked-statistics/disco-spec/master/discovery.ttl">Turtle</a> file.</li>
</ul>
<p></p>
<p>
There is also a <a href="https://raw.github.com/linked-statistics/disco-spec/master/discovery.xml">non-canonical RDF/XML version</a> of the Turtle file.
</p>
<p>
Open issues are discussed on the issue tracker: <a href="https://github.com/linked-statistics/disco-spec/issues">open issues</a>.
</p>
<p>
A detailed overview of the Disco vocabulary is available as <a href="http://www.essepuntato.it/lode/owlapi/https://raw.github.com/linked-statistics/disco-spec/master/discovery.ttl">LODE view</a>
or a <a href="http://vowl.visualdataweb.org/webvowl/index.html#iri=http://rdf-vocabulary.ddialliance.org/discovery.ttl">web view</a> using the web application <a href="http://vowl.visualdataweb.org/webvowl.html">Web-based Visualization of Ontologies</a>.
</p>
<p>
For a detailed explanation of DDI terms please refer to <a href="#overview">section 2</a>.
</p>
<section id="scope-and-purpose">
<h3 id="x2-1-scope-and-purpose"><span class="secno">2.1 </span>Scope and Purpose<a class="self-link" aria-label="§" href="#scope-and-purpose"></a></h3>
<p>This specification is designed to support the discovery of
microdata sets and related metadata using RDF technologies in the
Web of Linked Data. Many archives and other organizations have
large amounts of data, sometimes publically available, but often
confidential in nature, requiring applications for access. Many
such organizations use the
<a href="http://www.ddialliance.org/what">Data Documentation Initiative</a>
standard, which is a proven and highly detailed XML metadata
format for describing rectangular data sets of this type.
This vocabulary makes use of the DDI specification to create a
simplified version of this model for the discovery of data files.</p>
<p>The data holdings of data archives are often collected by
researchers, and only afterwards disseminated by archives. Other
data-producing organizations such as research centers and
statistical agencies are also increasingly interested in the
DDI standards for documenting their own microdata. In general
terms, most DDI metadata describes data sets for the social,
behavioural, and economic sciences. This data is fairly
consistent in format, consisting of rectangular data files with
columns containing variables for a set of cases, contained in
the rows. It is often collected by survey, although in some
cases may come from administrative sources, sensors, or
registers.</p>
<p>This vocabulary is intended not only for use by the research
data community, but also by any others needing an RDF vocabulary
for describing this type of rectangular data. This vocabulary
will provide a useful model for describing some of the data sets
now being published by open government initiatives, by providing
a rich metadata structure for them. While the data sets may be
available (typically as CSV files) the metadata which
accompanies them is not necessarily coherent, making the
discovery of these data sets difficult. This vocabulary would
help to overcome this difficulty by allowing for the creation of
standard queries to programmatically identify data sets, whether
made available by government or held within a data archive.</p>
<p>
Disco could be used to discover datasets by searching for specific questions, topics, and geographical coverage.
Depending on the complexity of the search respectively of the data portal, parts of Disco could be used, the complete Disco, or Disco together with related vocabularies.
The document [<cite><a class="bibref" href="#bib-Scenarios">Scenarios</a></cite>] by Vompras, Gregory, Bosch, Capadisli, and Wackerow describes typical use cases for the applicability of the DDI-RDF Discovery vocabulary. In the Section <a class="bibref" href="#use-cases-and-example-queries">Use Cases and Example Queries</a> of the Appendix additional discovery use cases are illustrated by several SPARQL queries.</p>
</section>
<p>
Statistical domain experts (core members of the DDI Alliance Technical Implementation Committee,
representatives of national statistical institutes, national data archives) and Linked Open Data community
members have selected the DDI elements which are seen as most important to solve problems associated with
use cases in the area of data discovery. Section 2 gives an overview of the conceptual model.
More detailed descriptions of all the properties are given in the specification and two conference papers [<cite><a class="bibref" href="#bib-Linked-Statistical-Data">Linked-Statistical-Data</a></cite>] [<cite><a class="bibref" href="#bib-DDI-RDF-Discovery-Vocabulary">DDI-RDF-Discovery-Vocabulary</a></cite>].
Disco is intended to provide means to describe microdata by essential metadata for the discovery purpose.
Existing DDI-XML instances can be transformed into this RDF format and therefore exposed as Linked Data.
The vice-versa process is not intended, as we have defined Disco components and reused components of other
RDF vocabularies which make only sense in the Linked Data field.
</p>
<section id="about-ddi">
<h3 id="x2-2-about-ddi"><span class="secno">2.2 </span>About DDI<a class="self-link" aria-label="§" href="#about-ddi"></a></h3>
<p>The Data Documentation Initiative standards are produced and
maintained by a member-based consortium of global scope, the
<a href="http://www.ddi-alliance.org/">DDI Alliance</a>. Housed
currently at the
<a href="http://www.icpsr.umich.edu/">Interuniversity Consortium
for Political and Social Research</a> (ICPSR) at the University
of Michigan, there are currently more than 30 member
institutions. The standards have been under development for more
than ten years, and are in widespread use among data archives
and libraries, producers of research data, secure data centers,
and statistical agencies.</p>
<p>There are two major versions of DDI (both serialied in XML format): the
“<a href="http://www.ddialliance.org/Specification/DDI-Codebook/">Codebook</a>”
version, which allows for holding general information
about a study, along with its data dictionary; and the
“<a href="http://www.ddialliance.org/Specification/DDI-Lifecycle/">Lifecycle</a>”
version of DDI, which allows for the description of more complex
multi-wave studies, throughout the data lifecycle, from study
conception through data collection and processing.</p>
<p>This vocabulary contains a selection of the major types of metadata defined by these two versions in a highly simplified form, for the purposes of discovery. The XML
Codebook and Lifecycle versions of DDI are very broad: these
standards contain hundreds of metadata elements, providing
enough information to programmatically work with the data files
for such functions as the automatic creation of databases, and
transformations between statistical packages. DDI in both
versions is generally used to describe data found in ASCII
files, whether positional files with fixed-width fields or files
using a delimited format such as CSV.</p>
<p>It is difficult to claim that there is a single agreed
conceptual model for describing research data in the social,
behavioural, and economic sciences—there is a wide range of
models and terms. However, the issues faced in this area have
been the subject of discussion within the DDI community for many
years, and the DDI model represents the best consensus which
exists today. As such, it gives us a good basis for creating a
vocabulary which will be recognizable to researchers familiar
with this type of data.</p>
</section>
<section id="relationship-to-data-cube-dcat-and-xkos">
<h3 id="x2-3-relationship-to-data-cube-dcat-and-xkos"><span class="secno">2.3 </span>Relationship to Data Cube, DCAT and XKOS<a class="self-link" aria-label="§" href="#relationship-to-data-cube-dcat-and-xkos"></a></h3>
<p>The Discovery Vocabulary (Disco) is aligned to several other metadata
vocabularies used in the RDF community. Disco is designed to be used in conjunction with other vocaularies.</p>
<p>The <a href="http://www.w3.org/TR/vocab-dcat/">Data Catalog
Vocabulary</a> (DCAT) is a <abbr title="World Wide Web Consortium">W3C</abbr> standard for describing catalogs
of datasets, and we map to it in two places:
Our <code><a href="#dfn-disco-logicaldataset" class="internalDFN">LogicalDataSet</a></code> is a subclass of DCAT’s Dataset, and our
<code><a href="#dfn-disco-datafile" class="internalDFN">DataFile</a></code> is a subclass of DCAT’s Distribution. DCAT makes few
assumptions about the kind of datasets being described,
and focuses on general metadata about the datasets
(mostly using Dublin Core), and on different ways of
distributing and accessing the dataset, including availability
of the dataset in multiple formats. Combining terms from both
DCAT and the Discovery Vocabulary can be useful for a number of
reasons:</p>
<ul>
<li>Describing collections (catalogs) of research datasets (DCAT)</li>
<li>Providing additional information about physical aspects (file size, file formats) of research data files (DCAT)</li>
<li>Providing information about the data collection that produced the datasets in a data catalog (Disco)</li>
<li>Providing information about the logical structure (variables, concepts, etc.) of tabular datasets in a data catalog (Disco)</li>
</ul>
<p>DCAT is richer for the description of collections and catalogue. Disco supports richer descriptions of groups of datasets or individual datasets. In this spec, some of our examples are partially based on DCAT (and we will indicate when this is the case).</p>
<p>The <a href="http://www.w3.org/TR/vocab-data-cube/">Data Cube
vocabulary</a> is a <abbr title="World Wide Web Consortium">W3C</abbr> standard for representing data cubes,
that is, multidimensional aggregate data. Data cubes are often
generated by tabulating or aggregating record-level datasets.
For example, if an observation in a census data cube indicates
the population of a certain age group in a certain region is
12345, then this fact was obtained by aggregating that number of
individual records from a record-level (or “microdata”) dataset.
The Discovery Vocabulary contains a property “aggregation” (pointing from a Disco data set to a Data Cube dataset) that
indicates that a Cube dataset was derived by tabulating a
record-level dataset.</p>
<p>Data Cube provides for the description of the structure of
such cubes, but also for the representation of the cube data
itself, that is, the observations that make up the cube dataset.
This is not the case for the Discovery Vocabulary, which
only describes the structure of a dataset, but is not concerned
with representing the actual data in it. The actual data is
assumed to sit in a data file (e.g., a CSV file, or in a
proprietary statistics package file format) that is not represented
in RDF.</p>
<p>
The interplay of Data Cube and Disco needs further exploration regarding the relationship of aggregate data,
aggregation methods, and the underlying microdata.
The goal would be to drill down to the related microdata based on a search resulting in aggregate data.
On the one hand aggregate data are often easily available and gives a quick overview.
On the other hand microdata enable more detailed analyses.
</p>
<p>The use of formal statistical classifications is very common
in research data sets—these are treated in our vocabulary as
SKOS concepts, but in some cases those working with formal
statistical classifications may desire more expressive
capability than SKOS provides. To support such users, the DDI
Alliance also publishes
<a href="http://purl.org/linked-data/xkos">XKOS</a>, a
vocabulary which extends SKOS
to allow for a more complete description of such
classifications. While the use of XKOS is not required by this
vocabulary, the two are designed to work in complementary fashion.</p>
<p>More details on the relationship to Data Cube, DCAT and XKOS as well as to other vocabularies are provided in Section 9.</p>
</section>
</section>
<section id="overview">
<!--OddPage--><h2 id="x3-overview"><span class="secno">3. </span>Overview<a class="self-link" aria-label="§" href="#overview"></a></h2>
<!-- <div class="figure">
<img class="uml-diagram" src="diagrams/overview.png" alt="Vocabulary Overview"/>
</div>
-->
<figure id="fig-vocabulary-overview">
<img class="uml-diagram" src="diagrams/overview.png" height="964" width="1440" style="width: 792px;">
<figcaption>Figure <span class="figno">1</span> <span class="fig-title">Vocabulary Overview</span></figcaption>
</figure>
<p>To understand the DDI Discovery Vocabulary, there are a few
central classes, which can serve as entry points. The first of
these is the <code><a href="#dfn-disco-study" class="internalDFN">Study</a></code> class. A <b><code><a href="#dfn-disco-study" class="internalDFN">Study</a></code></b> in our model represents the
process by which a data set was generated or collected. Literal
properties include information about the funding, organizational
affiliation, abstract, title, version, and other such high-level
information. In some cases, where data collection is cyclic or
on-going, data sets may be released as a <b><code><a href="#dfn-disco-studygroup" class="internalDFN">StudyGroup</a></code></b>, where each
cycle or "wave" of the data collection activity produces one or
more data sets. This is typical for longitudinal studies, panel
studies, and other types of "series" (to use the DDI term). In
this case, a number of <code><a href="#dfn-disco-study" class="internalDFN">Study</a></code> objects would be collected into a
single <code><a href="#dfn-disco-studygroup" class="internalDFN">StudyGroup</a></code>.</p>
<p>Data sets have two representations in our model: a logical
representation, which describes the contents of the data set,
and a physical representation, which is a distributed file
holding that data. It is possible to format data files in many
different ways, even if the logical content is the same. In our
model the <b><code><a href="#dfn-disco-logicaldataset" class="internalDFN">LogicalDataSet</a></code></b> represents the content of the file
(its organization into a set of variables (<code><a href="#dfn-disco-variable" class="internalDFN">Variable</a></code>)). The <code><a href="#dfn-disco-logicaldataset" class="internalDFN">LogicalDataSet</a></code>
is an extension of the <code>dcat:DataSet</code> class. Physical, distributed
files are represented by the class <b> <code><a href="#dfn-disco-datafile" class="internalDFN">DataFile</a></code></b> (not depicted in the diagram), which is itself an
extension of the <code>dcat:Distribution</code>.</p>