The Global Publication Output in Augmented Reality Research: A Scientometric Assessment for 1992-2019

1.1 Literature Review

The bibliometric studies in the field AR including its broader areas is limited to a few publications. Billinghurst (2018) provides an overview of AR research, analyzes the global research output by leading countries, organizations and authors. Dey et al. (2018) reviewed and classified 10-year literature covering AR user studies literature (consisting of 291 papers) from 2005 to 2014. Cipresso et al. (2018) explored the global research output on virtual reality and AR (21,667 and 9944 papers respectively) from 1990 to 2018, using the WoS database. Network and cluster analysis techniques were used to show changes in research productivity over time in the field. Karakus, Ersozlu, and Clark (2019) examined the global publications (437) on the application of augmented reality (AR) in the education sector published during 1999-19. The paper evaluated publication countries, institutions, journals, and authors as well as studied co-occurrences of author keywords. Gupte (2019) examined research field intersecting augmented reality and health Informatics (7360 publications). The findings are based on analysis of publications as well as social media output on measures such as publication output, top authors, affiliations, subject areas and geographical location. Yung and Khoo-Lattimore (2019) examined the applications of virtual reality and augmented reality (AR) in tourism sector using 46 manuscripts. Choi, Jung, and Noh (2015) analyzed 154 articles relevant to virtual reality’s application to manufacturing, exploring the trends in the past and present research and discussed the future of virtual reality research.

Similar kind of bibliometric studies assessing global literature in virtual reality and mixed reality do exist in the literature. Gupta and Dhawan (2019) and Gupta et al. (2019) examined virtual reality research output (91,429) during 1996–2017 and mixed reality research (2415) published during 1994-17 on a series of aspects, such as the growth rate, global share, citation impact, share of international collaborative publications, distribution of publications by broad subjects, productivity and citation profile of top countries, organizations and authors, preferred media of communication and bibliographic characteristics of highly-cited publications.

Although past research studies did evaluate AR research but the data sets covered in such bibliometric studies were rather small, limited to select few publication years. Until now there has been hardly any bibliomeric study that attempted to analyze AR research based on a comprehensive data set. This paper seeks to fill this gap. It will aim to evaluate AR research since its inception in 1992 till 2019 and discuss how growth in its applications overtime shaped the dynamics of research in the subject.

4.1 Growth Analysis

Augmented Reality (AR) research conducted across the world accumulated a total of 20, 228 publications during 1992-19. The annual publications output in the subject registered significantly hi,gh 54.23% annual growth, increasing in its annual volume from just 2 in 1992 to 3077 publications in 2019. The global output averaged to 788.5 papers per year. Its 14-year publications output registered 994.05% absolute growth, up from 1,849 in 1992-05 to 20,229 publications in 2006-19 which implies that research growth in the subject was significantly faster in the second-half period of the study compared to the fist-half (Table 1, Fig. 1).

Table 1.

Annual & Cumulative Global Publications Output in Augmented Reality Research, 1992-19

Fig. 1.

Augmented Reality Research - Global Growth in Publications Output 1992-2019

The 28-year citation impact of AR research averaged to 8.90 citations per publication (CPP) during 1992-19, although its 14-year citation impact declined from 30.32 CPP in 1992-05 to 6.94 CPP in 2006-19. The citation impact of the research was the highest 497.5 CPP in 1990 (Fig. 2).

Fig. 2.

Augmented Reality Research - Citations per Paper 1992-2019

Of the total global publications in AR, 69.41% (5324) appeared as conference papers, 25.17% (5356) as articles, 2.33% (514) as book chapters, 1.51% (334) as reviews, and others less than 1.0: 0.43% (94) as conference reviews, 0.32% (53) editorials, 0.24% (52) as notes, 0.14% (30) as books, 0.12% (26) as short surveys, 0.09% (19) as letters, etc.

4.2 Top 15 Most Productive Countries in Augmented Reality

Top 15 countries in AR research collectively contributed 87.05% global publications share and accounted for citations impact 10.23 CPP, above the world average 0f 8.90 CPP (Table 2, Fig. 3). Individually their global publication share differs widely from 1.75% to 19.25%. The USA contributed the highest publication share of 19.25%, followed by Germany (9.74%), Japan (9.05%), etc. India and Austria positioned at the bottom end of the tally with contributed 1.75% to 2.19% global publications share. There is some change of ranking order of countries in global share from 1992-05 to 2006-19. Only four countries registered their relative citations index above their group average (1.15): the U.K. (2.05), Austria (2.0), USA (1.81) and Canada (1.64).

Table 2.

Global Publication Share of Top 15 Most Productive Countries in Augmented Reality Research during 1992-19

Fig. 3.

Augmented Reality Research - Most Productive Countries 1992-19 Global Publications Share Vs Av. Citations per Paper

101 countries contributed to global research in AR during 1992-19. However, the distribution of research output coming from these participating countries is highly skewed. Only a select few countries had contributed to publications productivity above the global average of 788.5 publications per year. Of the 101 countries, 44 produced as low output with 1-10 papers each, 29 countries produced from 11-50 papers each, 9 countries from 51-100 papers each, 25 countries from 101-500 papers each, 7 countries from 501-1000 papers each, 4 countries 1001-1700 papers each, 2 countries 2001-2200 papers each and 1 country, the USA, produced 4254 papers. Table 2 shows the leading countries which have produced the most AR papers (Fig. 3).

4.2.1 Collaboration among Top 10 Most Productive Countries

A closer examination of collaborative linkages across top 10 most productive countries in AR research reveal that the USA leads with highest 786 linkages, followed by Germany (443), U.K. (389), Japan (281), China (280), France (242), Italy (209), Spain (181), South Korea (172) and Taiwan (90). As seen from collaboration network Gephi graph (Fig. 4) in terms of distances between nodes and thickness size of the edges, it is evident that collaborative linkages made by Germany (190), China (133), U.K. (123) and Japan (108) with the USA were relatively greater compared to collaboration linkage between the USA and the remaining countries including South Korea, Italy, France, Spain, and Taiwan (Table 3, Fig. 4).

Table 3.

Number of Collaborative Linkages among Top 10 Most Productive Countries in AR during 1992-19

Fig. 4.

Augmented Reality Research 1992-2019: Collaboration Network of Top 10 Countries

4.3 Distribution of Research Output by Sub-Fields

The global publication output in AR research distributed across top ten disciplines -- as identified in the Scopus database classification -- revealed that computer Science is the most popular area of research in AR research (74.85% share), followed by engineering (36.26%), mathematics (18.01%), social sciences (9.94%) and other disciplines from 1.75% to 6.93% during 1992-19. The change in research activity across identified disciplines between 1992-05 and 2006-19 was examined. The disciplines that showed increase in their research activity between the periods 1992-05 and 2006-19, from below to above the world average, include: engineering (from 96.79 to 100.29), social sciences (from 27.76 to 106.60), business, accounting & management (from 17.06 to 107.58), decision science (from 78.21 to 101.99) and arts & humanities (from 24.75 to 106.88). The disciplines that showed downfall from above to below average include computer science (from 103.03 to 99.72), mathematics (from 103.31 to 99.70), physics & astronomy (from 105.36 to 99.51), medicine (from 158.98 to 94.61) and materials science (from 125.84 to 97.64) (Table 4).

Table 4.

Subject-Wise Breakup of the Global Publications in AR Research during 1992-19

4.4 Types of Augment Reality (AR) Research

The distribution of AR research by various AR - types reveal that Trigger AR type contributed the largest global publications share 3.96% (874 papers), followed by Markerless AR type 1.58% share (348 papers), Projection-based AR type 0.62% share (136 papers), Superimposition-based AR type 0.27% share (59 papers), Outlining AR type 0.14% share (31 papers) and View-based AR type 0.10% share (22 papers). Within Trigger AR research, Location-based AR contributed the largest share 1.97%, followed by Marker-based AR (1.49%), Dynamic Augmentation (0.29%) and Complex Augmentation (0.27%). Their 14-year cumulative global publication share witnessed marginal to substantial fluctuations during the period between 1992-05 and 2006-19 (Table 5).

Table 5.

Classification of Global Output by Types of Augment Reality during 1992-19

4.5 AR Application Areas

Global publications share of AR applications vary from sector to sector. In the education sector, it was the largest 15.65% (3456 publications), followed by AR applications in industry including the manufacturing sector 10.78% (2380 papers), medical sector 7.20% (1590 papers), commerce 3.61% (797 papers), industrial and product design 2.86% (631 papers), tourism 2.0% (441 papers), video games 1.56% (345 papers), etc. (Table 6).

Table 6.

Classification of Global Output in Augment Reality Research by Type of Application

Global share of AR applications witnessed fluctuations over time. In education sector, it increased significantly from 4.06% to 16.71% during the period between 1992-05 and 2006-19, followed by AR applications in industry sector (from 7.03% to 11.12%), commerce (2.87% to 3.68%), %), industrial and product design (from 1.35% to 3.0%), tourism (from 0.54% to 2.13%), video games (from 0.70% to 1.64%), etc. On the other hand, global publications share of AR applications in medical sector witnessed decline from 10.92% to 6.86% (Table 6).

4.6 Top 50 Most Productive Organizations

During the period under study, a total of 5244 organizations published 22078 publications in AR research with an average of 4.21 publications per organization. The distribution of research publication across participating organizations is highly skewed. Of these 5244 organizations, 4226 contributed 1-10 papers each, 521 organizations 11-20 papers each, 389 organizations 11-50 papers each, 83 organizations 51-100 papers each and 25 organizations 101-342 papers each. The productivity of 50 most productive organizations in global AR research varied from 73 to 342 publications.

Of the top 50 organizations, 13 were from USA, 6 from Japan, 5 from China, 4 from Germany, 3 from South Korea, 2 each from Austria, France, Italy, Singapore and United Kingdom and 1 each from Australia, Brazil, Finland, Italy, Malaysia, New Zealand, Spain, Switzerland and Taiwan. Together the top 10, 20, 30, 40 and 50 organizations accounted for 9.93% (2192 publications), 16.10% (3555), 20.69% (4567), 24.62% (5435) and 28.14% (6213) of global publication share and 18.71% (36769 citations), 34.37% (67539), 44.73% (87883), 50.37% (98966) and 53.92% (105945) global citation share in 28 years during 1992-19. The scientometric profile of the 10 most productive organizations and of the 10 top organizations in terms of citation per paper and relative citation index is presented in Table 7. On further analysis, it was observed that:

• • Sixteen organizations registered had a higher publication output than the group average of 124.26: Technical University of Munich, Germany (342 papers), Osaka University, Japan (228 papers), University of South Australia (217 papers), University of Tokyo, Japan (212 papers), National University of Singapore (211 papers), Technical University of Graz, Austria (208 papers), Beijing Institute of Technology, China (200 papers), etc.
• • Sixteen organizations registered had a higher citation impact and relative citation impact above the group average of 17.05 citations per publication and 1.92 relative citation impact: Nara Institute of S&T, Japan (66.55 and 7.48), Imperial College, London, U.K. (57.14 and 6.42), Columbia University in the City of New York, USA (50.09 and 5.63), University of Washington, USA (50.03 and 5.62), MIT, USA (42.78 and 4.81), Carnegie Mellon University, USA (37.71 and 4.24), Georgia Institute of Technology, USA (31.36 and 3.52), University of North Carolina at Chapel Hill, USA (29.0 and 3.26), etc.

Table 7.

Scientometric Profile of Top 10 Most Productive Global Organizations and Top 10 Most Impactful Organizations in Augmented Reality Research during 1992-2019

4.6.1 Institutional Collaboration among Top 15 Most Productive Organizations

Nara Institute of S&T, Japan (59 linkages), Keio University, Japan (54 linkages) and Osaka University, Japan (50) rank top for registering highest institutional collaboration linkages. On the other hand CNRS Centre National de la Researche Scientifique, France (1 linkage), University of Tokyo, Japan (4 linkages) and MIT, USA (8 linkages) rank at bottom with least collaboration linkages (Table 8).

Table 8.

Institutional Collaboration among Top 15 Productive Organizations in AR during 1992-2019

4.7 Top 50 Most Productive Authors

7537 authors accumulated 22078 publications in AR research with an average of 2.92 publications per author during 1992-19. Their distribution is observed to be highly skewed: 6703 contributed 1-10 papers each, 685 authors 11-20 papers each, 129 authors 11-50 papers each, 16 authors 51-100 papers each and 4 authors 101-250 papers each. The publication productivity of top 50 authors in AR research varied from 35 to 250 publications. Together the top 10, 20, 30, 40 and 50 authors accounted for 5.58% (1232 publications), 8.89% (1963), 11.08% (2446), 12.99% (2868) share of global publications and 14.74% (3255) publication share and 13.68% (26873 citations), 22.18% (43579), 25.31% (49720), 28.47% (55939) and 30.95% (60802) share of global citations in 28 years during 1992-19. The scientometric profile of the top 10 most productive authors and top 10 authors in terms of citation per paper and relative citation index is presented in Table 9. On further analysis, it was observed that:

• • Sixteen authors registered had a higher publication output than the group average of 64.30: M. Billinghurst (250 papers), N. Navab (160 papers), D. Schmalstieg (149 papers), H. Kato (111 papers), G. Klinker (99 papers), B.H. Thomas (98 papers), etc; and
• • Eighteen authors organizations registered had a higher citation impact and relative citation impact above the group average of 18.91 citations per publication and 2.12 relative citation impact: S. Feiner (71.17 and 8.0), B. MacIntyre (58.22 and 6.54), H. Kato (35.38 and 3.98), H. Fuchs (34.40 and 3.87), T. Hollerer (33.85 and 3.80), G. Reitmayr (32.66 and 3.67), W. Piekarski (32.59 and 3.66), D. Schmalstieg (31.21 and 3.51), M. Billinghurst (29.52 and 3.32), etc.

Table 9.

Scientometric Profile of Top 10 Most Productive Global Authors and Top 10 Most Impactful Authors in Augmented Reality Research during 1992-2019

4.7.1 Collaboration among Top 20 Most Productive Authors

S.K. Ong, A.Y.C. Nee and Y. Liu registered the highest collaborative linkages (92, 92 and 78 respectively) and X. Wang, V. Teichrieb and W. Woo registered the least (1, 1 and 4). On the other hand, G. Klinker, S. Feiner and K. Kiyokawa lead the authors list in terms of highest collaborating authors (7 authors each). In terms of author to author collaborative linkages, it was the strongest between S.K. Ong - A.Y.C.Nee (85), Y.Liu - Y.Wang (51), D. Schmalstieg - C. Sandor (36), M.Billinghurst - H. Kato (27) (Table 10).

Table 10.

Collaboration Linkages among Top 20 Most Productive Authors in AR during 1992-2019

4.8 Medium of Research Communication

Of the total research output in the AR field, 70.45% (12571) appeared in conference proceedings, 27.09% (5982) in journals, 1.84% (406) in book series, 0.62% (406) in trade publications and rest undefined. The top 50 journals contributed 16 to 151 papers each in 28 years during 1992-19.

The top 50 journals together accounted for 28.77% (1721) share of the total AR output in journals medium. The top 5 most productive journals include the IEEE Transactions on Visualization & Computer Graphics (151 papers), Multimedia Tools & Applications (94 papers), Virtual Reality (72 papers), Computers & Graphics Pergamon (69 papers) and IEEE Computer Graphics & Applications (64 papers). The top 5 journals in terms of high citations per paper include Presence. Teleoperators & Virtual Environment (41 papers and 115.1 CPP), IEEE Pervasive Computing (24 papers and 96.29 CPP), IEICE Transactions on Information & Systems (20 papers and 88.55 CPP), Computers & Education (37 papers and 85.73 CPP) and IEEE Computer Graphics & Applications (64 papers and 59.17 CPP) (Table 11).

Table 11.

Top 10 Most Impactful Journals in terms Citation Per Paper in Augmented Reality Research during 1992-19

4.9 Highly Cited Papers

Of the total 22078 papers that appeared in the field of augmented reality during 1992-19, just 1.02% (226 papers) registered 100 and above citations per paper.

• • Of the 226 highly cited papers, 157 received 100-199 citations per paper, 41 had 202-299 citations per paper, 17 had 308-499 citations per paper, 5 had 543-895 citations per paper, 5 had 1214-1968 citations per paper and 2 papers had 2101-3433 citations per paper since their publication.
• • These 226 highly cited papers accumulated a total of 59859 citations, with an average of 264.86 citations per paper.
• • Of the 226 highly cited papers, 121 were by such organizations that pursued research in their standalone capacity per paper (non-collaborative) and 105 were by others who pursued research in their capacity as collaborative organizations per paper (51 national collaborative and 54 as international collaborative organizations).
• • Research participation in the 226 highly cited papers was the largest by USA (106 papers), followed by U.K (30 papers), Japan (18 papers), Canada (13 papers), Germany (12 papers), Austria (11 papers), France and Spain (10 papers each), Taiwan (9 papers), Switzerland (7 papers), Singapore and Australia (6 papers each), China, South Korea, Finland, New Zealand and Greece (5 papers each), Poland (3 papers), Italy, Portugal, Belgium, Israel and Turkey (2 papers each) and Brazil, Egypt, India, Slovakia and Venezuela (1 papers each).
• • A total of 899 authors from 396 organizations contributed to 226 highly cited papers.
• • The research organizations that accounted for the largest number of highly cited papers include: Massachusetts Institute of Technology, USA (13 papers), Columbia University, USA and University of Washington, Seattle, USA (12 papers each), University of North Carolina at Chapel Hill, USA (9 papers), Microsoft Research, USA (8 papers), Georgia Institute of Technology, USA (7 papers), Mitsubishi Electric Research Laboratory, USA and Imperial College, London (6 papers each).
• • Of the 226 highly cited papers, 124 appeared as articles, 89 as conference papers, 11 as reviews and 1 each as editorial and book.
• • These 226 highly cited papers appeared in 73 national and international journals. Twelve papers appeared in the Computer and Education, followed by 7 papers each Communications of the ACM and Personal & Ubiquitous Computing, 5 papers each in ACM Transactions on Graphics, IEEE Trans on Computer Graphics and Applications and IEEE Trans on Medical Imaging, 4 papers each in Computer and Graphics (Pergamon), IEEE Trans on Pattern Analysis & Machine Intelligence and IEEE Trans on Visualization & Computer Graphics, 3 papers each in ACM Trans. on Computer-Human Interactions, Automation in Construction, Journal of Science Education & Technology and Presence, etc.