User:AKhatun/Wikidata Scholarly Articles Subgraph Analysis

Scholarly articles form a large portion of Wikidata, this has been established for some time. This page highlights the baseline analysis done on Scholarly articles in Wikidata. The aim is to identify not only what portion of Wikidata is schoalrly articles, but also how connected is it to other parts of Wikidata, how many users query this subgraph and what percentage of queries they are. The analysis is therefore divided into two parts:

• Analysis on Wikidata:
  • What are schoalrly articles
  • Number and percentage of Wikidata entities that are scholarly articles
  • How many entities connect to scholarly articles
  • How many entities do scholarly articles connect to
  • Rate of growth of scholarly articles
  • Number of authors that would be isolated from Wikidata if Scholarly articles were removed (meaning, these author entities were created probably only for the purposes of the articles they wrote.)

• Analysis of the WDQS SPARQL Queries:
  • What defines a query to be associated with scholarly articles
  • The number and percentage of queries associated with scholarly articles
  • The number and percentage of queries that require entities other than scholarly articles vs those that rewuire only scholarly articles

The Wikidata dump of 20210719 was used for the following analysis.
Ticket: T281854

Definition of Scholarly Articles

Research papers or books can be considered scholarly articles. This includes journals articles, conference papers, books etc. Wikidata has several types of entities to cover these. More technically speaking, the entities involved are:

• academic journal article: Q18918145
• scholarly article: Q13442814
• scientific journal: Q5633421
• scholarly conference abstract: Q58632367
• conference paper: Q23927052
• scientific conference paper: Q10885494
• And their subclasses

Most of these have overlaps with scholarly articles, and with themselves. Scholarly articles have the largest count (37M) while everything else combined is in the thousands (~130K, excluding those that are included in scholarly articles), therefore the analysis is more focused on scholarly articles than others. The 130K could be even less if the other article types have overlap among themselves. This is not an exhaustive list, but cover most of what we can call scholarly articles or papers or journal articles. A detailed tree diagram of how these entities are related can be found in Scholarly Articles' Tree in Wikidata.

Scholarly Articles

Number of Scolarly Articles

• Total entity count: 94M
• Number of entities that are instance of scholarly article: 37308158 (37.3M). 40% of all Wikidata entities are therefore schoalrly articles.

Number of triples related to Scholarly Articles

• Total triple count: 12819818340 (12.8B)
• Number of triples included within the scholarly articles: 6399256630 (6.4B). 50% of all triples are directly related to scholarly articles.

Technically, the triple related to scholarly articles come under the 'context' of items that are scholarly articles. Example context of an item is Q39790431 dump. The context count includes:

• + all triples in which the item is a subject
• + the statement triples that rise from these triples
• + triples that define the item itself
• - the refs and vals, as those are re-usable in other items.

Triples per article

i.e triples related to the artciles.

• Average triple per article: 171
• Minimum triple per article: 10
• Maximum triple per article: 41847

See examples of articles with high number of triples in Wikidata_Basic_Analysis#Items

Direct triples per article

i.e triples where scholarly article is the subject.

• Average direct triple per article: 84
• Minimum direct triple per article: 7
• Maximum direct triple per article: 16758

See examples of articles with high number of direct triples in Wikidata_Basic_Analysis#Top_Subjects

This raises the question: Are only a few articles responsible for this huge number of triples, or are the triples distributed evenly among the articles? So we look into the distribution of triples.

Distribution of triples per article

Distribution of the count of triples per article Number of triples Count of articles 10 to 100 10583118 100 to 1k 26626656 1k to 10k 96563 more than 40k 1821

Number of days to recovery

If 6.4B triples were to be removed from wikidata, given the current rate of growth, how long would it take for wikidata to get back to its original size again?
The growth rate of triples is not constant, but considering the growth an approximate straight line, in grafana dashboard, Wikidata grows at a rate of 4.77M triples per day. This rate was calculated from the number of triples at the start and end of a 90-day interval (11/3/21 to 6/6/21). It could be faster or a bit slower than this.

• Wikidata will take 1300 days = 44 months = appx. 3.6 years to get back to it's original size. This is a wide approximation, since the growth rate of wikidata is not constant.

Predicates of Scolarly Articles

• Total distinct predicates: Total distinct predicates of scholarly articles is 2107
• Non-wikidata predicates: 17 of these predicates are non-wikidata predicates, i.e unlike P31/P279 etc, they do not start with the prefix wikidata.org. These predicates form 60% of the scholarly article triples.
• Non-wiki predicates: 14 of these predicates don't start with wikidata.org or wikiba.se. These are 46% of the scholarly article triples.
• Descriptions: Descriptions of scholarly articles form 20.5% of the scholarly article triples. This is 10% of all wikidata triples. Recall that all descriptions (of all items) together forms 19.5% of the entire wikidata.
• External IDs: Of the predicates of scholarly articles, external IDs form #% of scholarly article triples, #% of all triples.

Top predicates

Top predicates of scholarly articles

Predicate	Predicate label	# of Triples	% of Scholary Article Triples	% of all Triples
http://schema.org/description		1321691671	20.654	10.252
http://wikiba.se/ontology#rank		773820830	12.092	6.002
http://www.w3.org/1999/02/22-rdf-syntax-ns#type		773788620	12.092	6.002
http://www.w3.org/ns/prov#wasDerivedFrom		691773237	10.810	5.366
http://www.wikidata.org/prop/P2860	cites work	263097842	4.111	2.041
http://www.wikidata.org/prop/statement/P2860	cites work	263097837	4.111	2.041
http://www.wikidata.org/prop/direct/P2860	cites work	263004896	4.110	2.040
http://www.wikidata.org/prop/qualifier/P1545	series ordinal	154088914	2.408	1.195
http://www.wikidata.org/prop/P2093	author name string	134315644	2.099	1.042
http://www.wikidata.org/prop/statement/P2093	author name string	134315587	2.099	1.042
http://www.wikidata.org/prop/direct/P2093	author name string	134227496	2.098	1.041
http://www.w3.org/2000/01/rdf-schema#label		74437634	1.163	0.577
http://www.wikidata.org/prop/statement/P31	instance of	40319296	0.630	0.313
http://www.wikidata.org/prop/P31	instance of	40319296	0.630	0.313
http://www.wikidata.org/prop/direct/P31	instance of	40319268	0.630	0.313
http://www.wikidata.org/prop/P1476	title	37524904	0.586	0.291
http://www.wikidata.org/prop/statement/P1476	title	37524903	0.586	0.291
http://www.wikidata.org/prop/direct/P1476	title	37523899	0.586	0.291
http://www.wikidata.org/prop/P577	publication date	37309627	0.583	0.289
http://www.wikidata.org/prop/statement/P577	publication date	37309626	0.583	0.289
http://www.wikidata.org/prop/statement/value/P577	publication date	37309625	0.583	0.289

Top properties

Considering only wikidata predicates, i.e mainly properties of items, and combining the direct, prop, and statements of the property, we get the following count of top predicates.

Top properties of scholarly articles

Property name	# of Triples	% of Scholary Article Triples	% of all Triples
cites work	789200575	12.332	6.122
author name string	402859029	6.296	3.125
series ordinal	154089316	2.408	1.195
publication date	149227733	2.332	1.156
DOI	134464365	2.100	1.045
instance of	120957868	1.890	0.939
title	112574265	1.758	0.873
published in	109147370	1.707	0.846
page(s)	104199512	1.629	0.807
volume	103612864	1.620	0.804
PubMed ID	95893499	1.499	0.744
issue	95083032	1.485	0.738
author	59439111	0.929	0.461
main subject	41515900	0.648	0.321
language of work or name	34801291	0.543	0.270
PMCID	19059585	0.297	0.147
ResearchGate publication ID	13734703	0.216	0.108
stated as	8609378	0.135	0.067
exact match	8162235	0.129	0.063
Dimensions Publication ID	4617733	0.072	0.036

Distribution of predicates

Distribution of distinct predicates per article is given below:

• Average distinct predicate per article: 29
• Maximum distinct predicate per article: 102
• Minimum distinct predicate per article: 7

Distribution of distinct predicate per scholarly article Number of distinct predicate Number of articles less than 10 277 10 to 20 152995 20 to 30 18146794 30 to 40 18294391 40 to 50 711176 50 to 60 2493 60 to 70 26 70 to 80 4 80 to 90 1 90 to 100 0 more than 100 1

Scholarly Articles' Author

Number of authors that would be isolated from Wikidata if Scholarly articles were removed (meaning, these author entities were created probably only for the purposes of the articles they wrote.)