1.
Measuring Metadata Quality
Péter Király
Comparative Studies (General and Comparative Literature and Cultural Studies)
Georg-August-Universität Göttingen
2019-06-24
slides: http://bit.ly/qa-defense

2.
metadata
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metadata
something else
here:
cultural heritage objects
★ describes
★ explains
★ locates
★ represents

3.
the problem
https://twitter.com/fxru/status/1052838758066868224
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4.
dates (MoMa collection)
Harald Klinke (LMU München) https://twitter.com/HxxxKxxx/status/1066805548866289664
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5.
title – thumbnail
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6.
multilinguality
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★ Mona Lisa → 456
results
★ La Gioconda → 365
results
★ La Joconde → 71
results
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7.
information
metadata data
consequence
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no metadata
no access to data no data usage
bad metadata
http://bit.ly/qa-defense Anonyme: Le Liseur © 2008 Hulton-Deutsch Collection / Corbis

8.
laws of library science
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http://bit.ly/qa-defense Anonyme: Le Liseur © 2008 Hulton-Deutsch Collection / Corbis
1. Books are for use.
2. Every person his or her book.
3. Every book its reader.
4. Save the time of the reader.
5. Library is a growing organism.
S. R. Ranganathan, 1931

9.
objective
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there are “good” and “bad” metadata records
functional requirements
(metrics)
good
acceptable
bad
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10.
metadata quality metrics in literature
Bruce and Hillman (2004); Ochoa and Duval (2009); Palavitsinis (2014); Zaveri et al. (2015)
https://www.zotero.org/groups/488224/metadata_assessment
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completeness
accuracy
consistency
...
correctness
objectiveness
appropriateness
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11.
complication
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★ lack of details
★ no shared implementation
★ not flexible (collection specificity)
★ not scalable
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12.
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★ Q1: What are the relevant quality dimensions in
two different cultural heritage data sources?
★ Q2: How could it be implemented in a flexible way?
★ Q3: How could it be implemented in scalable way?
★ Q4: How could Big Data analysis be conducted with
limited computational resources?
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questions

13.
structure is algorithmically measurable, content is not
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★ number of fields
★ uniqueness of values
★ language annotation
★ is it really the Mona Lisa?
★ is it about Lower Saxony?
★ is it in Polish?
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14.
hypothesis
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by measuring structural elements we
can approximate metadata quality
≃ metadata smell
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15.
LAM institution
workflow
1. ingest
2. measure records
3. aggregate
4. report
5. evaluate with experts
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improve records
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quality assessment tool

16.
Measuring Europeana
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17.
organisational approach
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Europeana Data Quality Committee
★ analysing/revising metadata schema
★ functional requirement analysis
★ problem catalog
★ multilinguality
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18.
technical approach
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“Metadata Quality Assessment Framework”
★ adaptable to different metadata schemas
★ scalable (to Big Data)
★ generates understandable reports for data curators
★ open source
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19.
what to measure?
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★structural and semantic features
completeness, cardinality, uniqueness, length, dictionary entry, data type
conformance, multilinguality (generic metrics)
★functional requirement analysis
★problem catalog
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20.
http://bit.ly/qa-defense
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21.
<#record> a ore:Proxy ;
dc:subject “Ballet”, “Opera” .
<#record> a ore:Proxy ; edm:europeanaProxy true ;
dc:subject <http://data.europeana.eu/concept/base/264>
, <http://data.europeana.eu/concept/base/247> .
<http://data.europeana.eu/concept/base/264> a skos:Concept .
skos:prefLabel "Ballett"@no, "बैले"@hi, "Ballett"@de, "Балет"@be, "Балет"@ru
, "Balé"@pt, "Балет"@bg, "Baletas"@lt, "Balet"@hr, "Balets"@lv .
<http://data.europeana.eu/concept/base/247>
skos:prefLabel "Opera"@no, "ओपेरा (गीतिनाटक)"@hi, "Oper"@de, "Ooppera"@fi
, "Опера"@be, "Опера"@ru, "Ópera"@pt, "Опера"@bg, "Opera"@lt .
multilinguality
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0
0
11 19
Distinct languages Tagged literals 1,7 Literals per language
dereferencing
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22.
19%
58%
63%
13.3% 23.7%
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23.
Measuring library
catalogues
Card catalogue at Gent University Library, photo: Pieter Morlion, 2010 CC-BY 4.0
https://commons.wikimedia.org/wiki/File:Boekentoren_2010PM_1179_21H9015.JPG
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24.
a (pretty printed) example
LDR 01136cnm a2200253ui 4500
001 002032820
005 20150224114135.0
008 031117s2003 gw 000 0 ger d
020 $a3805909810
100 1 $avon Staudinger, Julius,$d1836-1902$0(viaf)14846766
245 10$aJ. von Staudingers Kommentar zum ... /$cJ. von Staudinger.
250 $aNeubearb. 2003$bvon Jörn Eckert
260 $aBerlin :$bSellier-de Gruyter,$c2003.
300 $a534 p. ;.
500 $aCiteertitel: BGB.
500 $aBandtitel: Staudinger BGB.
700 1 $aEckert, Jörn
852 4 $xRE$bRE55$cRBIB$jRBIB.BUR 011 DE 021$p000000800147
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25.
semantic elements
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MARC 21 versions total
control fields 7 7
control subfields 211 211
data fields 215 68 283
indicators 175 8 183
subfields 2259 344 2603
3287
Java classes
qa-metadata-marc.jar
Avram JSON
data model
export
machine readable standard
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26.
proportion of records with issues
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library all core
bay 100.0 18.8
bzb 100.0 76.1
cer 2.8 2.8
col 90.4 66.0
dnb 13.9 0.2
gen 40.8 27.3
har 100.0 97.3
loc 30.5 29.3
library all core
mic 80.8 67.5
nfi 62.1 58.1
ris 99.7 57.1
sfp 82.7 60.4
sta 92.7 92.5
szt 30.8 30.6
tib 100.0 100.0
tor 100.0 74.2
core = issues in the documented elements
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strange
almost
error-less
surprising

27.
issue types
record level
★ ambiguous linkage
★ invalid linkage
★ type error
control field
★ invalid code
★ invalid value
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data field
★ missing reference
subfield (880$6)
★ non-repeatable field
★ undefined field
indicator
★ invalid value
★ non-empty value
★ obsolete value
subfield
★ classification
★ invalid ISBN
★ invalid ISSN
★ invalid length
★ invalid value
★ repetition
★ undefined subfield
★ non well-formatted
value
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most frequent issues

28.
completeness by field groups
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29.
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★ Q1 quality dimensions:
completeness, multilinguality, issue detection
★ Q2 flexibility:
schema abstraction, decoupling measurements
★ Q3 scalability:
using frameworks such as Apache Spark
★ Q4 limited resource:
measuring performance, optimizing parameters
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conclusions

30.
publications
★ J. Stiller, P. Király (2017) Multilinguality of Metadata Measuring the Multilingual Degree of
Europeana’s Metadata. In Proc. of the 15th Intl. Symp. of Information Sci. 164–176.
★ P. Király (2017) Towards an extensible measurement of metadata quality. In Second International
Conference on Digital Access to Textual Cultural Heritage. 111–115. 10.1145/3078081.3078109
★ P. Király (2017) Measuring completeness as metadata quality metric in Europeana. In Digital
Humanities 2017 Conference Abstracts. 291–293.
★ V. Charles, J. Stiller, P. Király, W. Bailer, N. Freire (2017) Evaluating Data Quality in Europeana:
Metrics for Multilinguality. In Joint Proceedings of TDDL 2017, MDQual 2017 and Futurity 2017
★ P. Király (2018) Adat a könyvtárban. In Hagyomány és újítás a 21. századi könyvtárban. 49–74.
★ P. Király, M. Büchler (2018) Measuring completeness as metadata quality metric in Europeana. In
2018 IEEE International Conference on Big Data. 2711–2720. 10.1109/BigData.2018.8622487
★ P. Király, J. Stiller, V. Charles, W. Bailer, N. Freire (2019) Evaluating Data Quality in Europeana:
Metrics for Multilinguality. In Metadata and Semantic Research 2018. 199–211. 10.1007/978-3-
030-14401-2_19
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31.
conferences
#1 International Symposium on Information Science 2017, Berlin (with Juline Stiller) #2 #dariahTeach
2017, Lausanne (poster) #3 SI & IT Workshop 2017, Göttingen (with Juline Stiller) #4 Linked Data
Quality workshop (@ ESWC 2017), Portorož (invited keynote speech) #5 DATeCH 2017, Göttingen
#6 ELAG 2017, Athens (with Valentine Charles) #7 Digital Humanities 2017, Montréal #8 Linked Data
Quality Workshop (@ Semantics 2017), Amsterdam (organizer and presenter) #9 (Meta)-Data Quality
Workshop (@ TPDL 2017), Thessaloniki (presented by Juliane Stiller) #10 ADOCHS meeting 2017,
Brussels (invited speech) #11 LDCX 2018, Stanford University #12 ELAG 2018, Prague (workshop
together with Anette Strauch, Patrick Hochstenbach, Mark Phillips) #13 12th International Conference
on Metadata and Semantics Research 2018, Limassol (with Juliane Stiller) #14 Open Research Knowledge
Graph workshop 2018, Hannover #15 Research Infrastructure on Religious Studies Workshop on FAIR
Research Data Management 2018, Mainz (invited speech) #16 Computational Archival Science
workshop (@ IEEE Big Data 2018), Seattle #17 DATeCH 2019, Brussels
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