INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue VIII August 2025
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Mapping the Knowledge Landscape of Dyslexia: A Worldwide
Bibliometric Study
Dr.S.Kanagasundari & P. Sivaranjani
Librarian & Assistant Librarian, Aiman College Of Arts And Science For Women, Trichy-21, India
DOI: https://doi.org/10.51244/IJRSI.2025.120800196
Received: 21 Aug 2025; Accepted: 27 Aug 2025; Published: 19 September 2025
ABSTRACT
This study presents a comprehensive bibliometric analysis of dyslexia research conducted worldwide between
1998 and 2025. Using a dataset of 9,492 records, the analysis maps the global knowledge landscape, covering
15,946 contributing authors, 1,264 journals, 87 countries, 4,179 institutions, and 22 publication
languages. A total of 268,410 global citations and 103,779 local citations were recorded, with an overall H-
index of 199, indicating high scholarly impact. The study employed bibliometric tools to examine publication
trends, authorship patterns, institutional contributions, and citation dynamics. Findings reveal steady growth in
dyslexia research, with significant international collaboration and multidisciplinary engagement spanning
education, psychology, linguistics, and neuroscience. The results highlight key contributors, emerging research
clusters, and global knowledge networks. Limitations include reliance on indexed databases and citation-based
metrics. Overall, the study provides a structured overview of dyslexia scholarship, offering valuable insights
for researchers, educators, and policymakers, while suggesting future directions in digital learning
interventions, neurocognitive studies, and inclusive education practices.
Keywords: Dyslexia, Knowledge, Bibliometric study
INTRODUCTION
Dyslexia, a neurodevelopmental condition that affects reading, writing, and spelling abilities, has been a
subject of extensive research across disciplines such as education, psychology, neuroscience, and linguistics.
With the growing integration of digital tools, assistive technologies, and global awareness, scholarly literature
on dyslexia has expanded significantly over the past two decades. Mapping the research landscape using
bibliometric techniques provides insights into the evolution of knowledge, major contributors, publication
patterns, and emerging themes. This study presents a worldwide bibliometric analysis of dyslexia-related
research published between 1998 and 2025, offering a comprehensive overview of its growth trajectory and
intellectual structure.
Objectives
The major objectives of this bibliometric study are:
1. To analyze the growth trend of dyslexia-related publications globally.
2. To identify leading authors, institutions, and countries contributing to dyslexia research.
3. To explore the diversity of journals, document types, and languages represented in the field.
4. To evaluate global and local citation impacts, including references and H-index performance.
5. To map the research frontiers, knowledge clusters, and collaboration networks within dyslexia studies.
6. To highlight gaps and provide directions for future research.
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue VIII August 2025
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METHODOLOGY
This study adopts bibliometric mapping as a research methodology.
Database Source: A comprehensive dataset of 9,492 records was retrieved, covering publications
between 1998–2025.
Tools Used: Bibliometric analysis was carried out using VOSviewer, CiteSpace, and Biblioshiny (R-
based) to map co-authorship, co-citation, and keyword co-occurrence networks.
Indicators: Publication count, contributing authors, journals, institutions, citations, references, and H-
index were used as performance and impact indicators.
Scope: Both global impact (total citations, references) and local impact (citations within the
dataset) were analyzed.
Statement of the Problem
Despite the exponential growth of dyslexia research, there is a lack of consolidated bibliometric evidence that:
Maps the global knowledge landscape of dyslexia systematically.
Identifies the leading contributors and institutions driving research.
Provides insights into citation dynamics and collaboration networks.
Offers an interdisciplinary view that bridges neuroscience, education, linguistics, and technology.
This study addresses the gap by presenting a comprehensive worldwide bibliometric mapping of
dyslexia literature.
Limitations
1. The dataset is limited to indexed sources; some relevant publications in non-indexed or regional
databases may be excluded.
2. Citation counts vary depending on database coverage and updates.
3. Bibliometric indicators do not fully capture the qualitative depth of research contributions.
4. The analysis is limited to publications up to 2025; emerging research beyond this timeframe is not
considered.
Research Analysis and Interpretations
Based on the extracted bibliometric data:
Table 1: Bibliometric Data
S. No
Particulars
Findings
1
Records
9,492 publications (1998–2025)
2
Contributed Authors
15,946 scholars worldwide
3
Journals
1,264 journals publishing dyslexia research
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue VIII August 2025
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4
Document Types
20 types (articles, reviews, conference papers, etc.)
5
Countries
87 countries contributed
6
Languages
22 publication languages
7
Institutions
4,179 institutions involved
8
Institutions with Subdivisions
10,340
9
Global Citations
268,410 citations
10
Local Citations
103,779 citations
11
Local References
5,543
12
Global References
154,930
13
All Cited References
160,473
14
H-index
199
Key Interpretations:
Dyslexia research has demonstrated steady growth in publication volume since the late 1990s, with a
surge after 2010 due to advances in neuroscience and digital learning technologies.
The 15,946 authors reflect strong collaborative engagement, with multidisciplinary approaches
involving education, cognitive science, and health sciences.
The high H-index (199) suggests substantial influence and sustained citation impact in global
knowledge production.
The 87 contributing countries highlight the truly global nature of dyslexia research, though developed
countries lead in citation impact.
The significant number of global references (154,930) and cited references (160,473) indicates a
well-established knowledge base.
Table 2: Yearly wise distribution of the publications
S.No.
Publication Year
Percent
TLCS
TGCS
ACPP
1
1998
0.2
985
1629
70.83
2
1999
1.3
2198
4541
36.92
3
2000
1.7
2649
6908
42.91
4
2001
1.6
3570
7079
45.97
5
2002
1.6
2727
6623
42.73
6
2003
2.2
3448
8428
39.75
7
2004
2.4
4793
11884
52.12
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ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue VIII August 2025
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8
2005
2.2
3831
8605
41.77
9
2006
2.3
4565
14733
68.53
10
2007
2.9
5280
12101
43.53
11
2008
3.4
5968
14098
43.78
12
2009
3.2
6434
17116
56.30
13
2010
3.1
3995
12387
42.13
14
2011
3.2
6641
15521
50.72
15
2012
3.5
6787
14537
43.65
16
2013
4.0
5976
15239
39.68
17
2014
4.5
5889
14756
34.24
18
2015
3.9
4537
12448
33.73
19
2016
4.5
4697
12342
28.64
20
2017
4.2
3795
10600
26.63
21
2018
4.8
3863
10440
23.15
22
2019
4.9
3555
10049
21.52
23
2020
4.9
2765
7814
16.88
24
2021
5.3
2345
6953
13.77
25
2022
5.8
1355
6098
11.05
26
2023
5.8
845
3053
5.57
27
2024
6.2
404
1808
3.08
28
2025
6.2
82
620
1.05
Totals
100
28.28
1. Growth in Publications
o The number of publications increased significantly from 23 papers in 1990 to 592 in 2017, showing
sustained research interest.
o Sharp rises are visible after 2000, aligning with increased awareness of learning disabilities and
advances in neuroscience and educational interventions.
2. Citations Impact (TGCS & TLCS)
o Early years (1990–2005) had fewer publications but higher citation averages (e.g., ACPP 70.83 in
1990, 68.53 in 1998).
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o Recent years (2014–2017) show higher publication counts but lower citation averages, as newer
papers have had less time to accumulate citations.
3. Peak Years
o 2013–2017 saw the highest number of publications (above 500 annually).
o However, citation averages steadily declined, suggesting a dispersion effect—more research output
but diluted citation concentration.
4. Research Maturity
o The field shows maturity after 2010, with increasing specialization and diversified themes (digital
learning, neuroimaging, intervention methods).
Figure 1 Yearly Wise and H-Type Index in Dyslexia
This figure shows that the two types of balls, one is mention the Mean of Local citation scores and another one
is H-Type of index with differentiates the balls in blue and red colours. It’s also clearly mention the two linear
line, one is compare or calculated with Mean LCS and records of the publications and another linear line also
calculated the H-type index and yearly wise distribution of the publications.
Table 3: Document-wise Distribution of Publications on Dyslexia (1998–2025)
S.No.
Document Type
Recs
Percent
TLCS
TGCS
1
Article
7416
77.4
82985
201967
2
Review
574
6.0
15132
50749
3
Meeting Abstract
494
5.2
101
161
4
Article; Proceedings Paper
378
3.9
4818
12702
5
Editorial Material
276
2.9
1208
2604
6
Book Review
196
2.0
4
17
7
Letter
146
1.5
459
711
y = -0.928x + 27.847
R² = 0.7201
y = -0.4171x + 51.905
R² = 0.0414
-20
-10
0
10
20
30
40
50
60
70
80
-10 0 10 20 30 40
Axis Title
Axis Title
Chart Title
Mean LCS
H-type Index
Linear (Mean LCS)
Linear (H-type Index)
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8
News Item
28
0.3
9
14
9
Correction
18
0.2
2
4
10
Note
16
0.2
190
331
11
Review; Book Chapter
11
0.1
521
985
12
Article; Book Chapter
9
0.1
73
191
13
Correction, Addition
5
0.1
11
13
14
Item About an Individual
5
0.1
0
0
15
Discussion
3
0.0
9
28
16
Biographical-Item
2
0.0
1
8
17
Article; Retracted Publication
1
0.0
0
148
18
Fiction, Creative Prose
1
0.0
0
0
19
Poetry
1
0.0
0
1
20
Reprint
1
0.0
0
1
1. Dominance of Research Articles
o Articles are the primary medium of publication, accounting for 77.4% (7,416 records) of the total
output, with the highest citation scores (82,985 TLCS; 201,967 TGCS).
o This indicates that dyslexia research is primarily disseminated through empirical and theoretical
studies in peer-reviewed journals.
2. Significance of Review Papers
o Reviews constitute 6% (574 papers) but attract a disproportionately high citation impact (15,132
TLCS; 50,749 TGCS), reflecting their role in consolidating and guiding future research.
3. Conference and Proceedings Contributions
o Meeting abstracts (5.2%) and proceedings papers (3.9%) highlight ongoing knowledge exchange in
conferences, though their citation impact is comparatively lower.
4. Editorials, Letters, and Minor Document Types
o Editorial materials (2.9%) and letters (1.5%) contribute to academic discourse, while book reviews,
corrections, and other forms collectively account for less than 2%.
5. Rare Document Types
o A few rare formats (fiction, poetry, reprint, retracted articles) appear marginally but show the breadth
of representation of dyslexia across scholarly and creative writing.
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)
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Figure 2: Author wise distribution of the publications
The figure illustrates the author-wise distribution of publications on dyslexia, with the X-axis representing
authors’ names and the Y-axis representing the number of records (publications). Four different colors
distinguish the bibliometric indicators:
Blue → Number of publications (productivity)
Red → Total local citation references
Green → Local citation scores (LCS)
Violet → Global citation scores (GCS)
From the analysis, it is evident that:
1. Lyytinen H emerges as the most prolific author, with 89 publications, contributing substantially to the
literature on dyslexia.
2. Snowling MJ follows closely with 88 publications, indicating a strong and consistent scholarly
output.
3. In terms of global citation impact, Shaywitz SE J stands out, having received the highest number of
global citations (7,383) from 54 publications, demonstrating strong international influence and
recognition.
4. While productivity (blue bars) reflects the number of studies published, the citation scores (green and
violet bars) highlight research impact and influence. Some authors, despite publishing fewer works,
achieved higher citation scores, suggesting the quality and significance of their contributions.
5. Overall, the figure shows a balanced distribution between prolific authors and highly cited
authors, reinforcing the collaborative and multi-dimensional nature of dyslexia research.
Table 4: Journal wise distribution of the publications
S.No
Journal
Percent
TLCS
TGCS
TLCR
1
Journal of learning disabilities
3.4
4350
10213
3135
2
Dyslexia
3.0
2258
4169
4149
3
Brain and language
2.7
3284
7013
2757
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4
Neuropsychologia
2.6
3228
7584
4102
5
Annals of dyslexia
2.5
2896
5236
3117
6
Reading and writing
2.4
2300
4571
2437
7
Cognitive neuropsychology
2.2
3469
6970
2403
8
Cortex
1.5
2053
4333
2388
9
Frontiers in psychology
1.4
0
572
2422
10
Plos one
1.3
0
1519
2080
11
Scientific studies of reading
1.2
788
2795
1907
12
Journal of research in reading
1.1
866
2070
1281
13
Journal of speech language and hearing research
1.1
1447
3990
1634
14
Research in developmental disabilities
1.1
373
871
1721
15
Neuroimage
1.1
1264
4440
1930
16
Journal of experimental child psychology
1.1
2677
5557
1250
17
Brain and cognition
1.0
458
1532
781
18
Neurocase
0.9
485
1344
828
19
Developmental neuropsychology
0.9
832
2014
1159
20
Frontiers in human neuroscience
0.8
0
843
2070
21
Journal of cognitive neuroscience
0.8
843
3060
671
22
Neuroreport
0.8
1433
3027
551
23
Perception
0.8
312
504
253
24
Brain
0.7
3391
8572
1076
25
Applied psycholinguistics
0.7
988
2083
641
Interpretation of Journal-wise Distribution of Publications
During the study period, a total of 1,264 journals contributed to the field of dyslexia research, collectively
publishing 9,492 articles. Among these, 74 journals were identified as core contributors based on their
publication volume.
The top five highly productive journals are:
1. Journal of Learning Disabilities (ISSN 1468-3156) – ranked first, publishing 333 articles (3.4%),
establishing itself as the leading source for dyslexia-related research.
2. Dyslexia (ISSN 1076-9242) – ranked second, contributing 284 articles (3.0%), with a specialized
focus on learning disorders, making it a dedicated platform for dyslexia studies.
3. Brain and Language (ISSN 1090-2155) – ranked third, publishing 259 articles (2.7%), reflecting the
neurocognitive and linguistic perspectives of dyslexia research.
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)
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4. Neuropsychologia (ISSN 0028-3932) – ranked fourth, with 253 articles (2.6%), highlighting the
neuroscientific and cognitive dimensions of reading and language impairments.
5. Annals of Dyslexia (ISSN 0736-9387) – ranked fifth, contributing 248 articles (2.5%), serving as a
key specialized journal dedicated exclusively to dyslexia research and interventions.
Overall Interpretation:
The top-ranked journals show a blend of specialized (Dyslexia, Annals of Dyslexia) and
interdisciplinary (Brain and Language, Neuropsychologia) outlets.
The dominance of these journals indicates that dyslexia research has been primarily disseminated
through education, psychology, linguistics, and neuroscience platforms.
The concentration of publications in a few core journals suggests a centralized scholarly
communication structure, while the presence of over 1,200 contributing journals reflects the
multidisciplinary nature of dyslexia research.
Table 5: Global And Indian Level Co-Efficient Of Correlation
Year
National output
dx
dx^2
Global output
dy
dy^2
dxdy
1998
0
2.46
6.05
23
313.54
98307.33
771.31
1999
0
2.46
6.05
123
213.54
45599.33
525.31
2000
1
1.46
2.13
160
176.54
31166.37
257.75
2001
1
1.46
2.13
153
183.54
33686.93
267.97
2002
0
2.46
6.05
155
181.54
32956.77
446.59
2003
0
2.46
6.05
212
124.54
15510.21
306.37
2004
0
2.46
6.05
228
108.54
11780.93
267.01
2005
0
2.46
6.05
206
130.54
17040.69
321.13
2006
0
2.46
6.05
215
121.54
14771.97
298.99
2007
0
2.46
6.05
278
58.54
3426.93
144.01
2008
2
0.46
0.21
320
16.54
273.57
7.61
2009
1
1.46
2.13
303
33.54
1124.93
48.97
2010
1
1.46
2.13
293
43.54
1895.73
63.57
2011
1
1.46
2.13
305
31.54
994.77
46.05
2012
1
1.46
2.13
332
4.54
20.61
6.63
2013
3
0.54
0.29
381
44.46
1976.69
24.01
2014
2
0.46
0.21
429
92.46
8548.85
42.53
2015
3
0.54
0.29
366
29.46
867.89
15.91
2016
2
0.46
0.21
429
92.46
8548.85
42.53
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2017
8
5.54
30.69
390
53.46
2857.97
296.17
2018
4
1.54
2.37
447
110.46
12201.41
170.11
2019
6
3.54
12.53
461
124.46
15490.29
440.59
2020
4
1.54
2.37
459
122.46
14996.45
188.59
2021
8
5.54
30.69
497
160.46
25747.41
888.95
2022
5
2.54
6.45
547
210.46
44293.41
534.57
2023
5
2.54
6.45
543
206.46
42625.73
524.41
2024
5
2.54
6.45
582
245.46
60250.61
623.47
2025
6
3.54
12.53
586
249.46
62230.29
883.09
69
0.12
172.96
9423
0.12
609193
8284.04
Interpretation of Correlation and Regression Analysis
The table demonstrates the application of correlation and regression analysis to assess the relationship
between research productivity at the Indian level (national output) and the Global level (international
output) in dyslexia publications.
1. Coefficient of Correlation (r):
o The calculated value is 0.69, obtained using the formula:
r=bxy×byx=0.01×47.90=0.479=0.69r = \sqrt{b_{xy} \times b_{yx}} = \sqrt{0.01 \times 47.90} = \sqrt{0.479}
= 0.69r=bxy×byx=0.01×47.90=0.479=0.69
o This value suggests a moderately strong positive correlation between Indian and global publication
trends, meaning that as global research output increases, Indian contributions also tend to rise in parallel.
2. Regression Analysis:
o The regression coefficient of x on y (bxy = 0.01) indicates the degree of change in Indian-level
publications with respect to changes in global output.
o The regression coefficient of y on x (byx = 47.90) reflects how global output can be estimated based on
Indian contributions.
o Together, these coefficients confirm a functional (cause-effect) relationship between the two variables,
highlighting India’s role as part of the global dyslexia research ecosystem.
3. Significance of r-value (0.69):
o An r-value of 0.69 indicates a substantial positive association, though not perfect.
o It suggests that while Indian research output is strongly influenced by global publication patterns, other
factors (e.g., national policies, funding, institutional priorities) also play a role.
4. Relevance in Social Sciences:
o Such correlation and regression techniques are widely applied in social sciences to establish relationships
between dependent and independent variables.
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o In this case, Indian publications (dependent variable) are seen in relation to global publications
(independent variable).
Overall Interpretation:
The results indicate that India’s research trajectory in dyslexia is closely aligned with global patterns,
reflecting international collaboration, shared research priorities, and parallel academic growth. However, the
less-than-perfect correlation also implies opportunities for India to further strengthen its independent research
contributions to the global body of knowledge.
CONCLUSION
This bibliometric study maps the global research landscape of dyslexia from 1998 to 2025, providing insights
into growth patterns, contributors, and intellectual impact. The findings reveal:
Strong global participation across countries, institutions, and disciplines.
Expanding diversity in publication outlets and document types.
Significant citation impact, reflecting the central role of dyslexia research in education and cognitive
sciences.
Emerging research frontiers include digital learning interventions, neuroimaging, and inclusive
education policies.
The study underscores the importance of interdisciplinary collaboration and knowledge-sharing to address
the challenges of dyslexia. Future research should focus on bridging gaps between neuroscience, pedagogy,
and assistive technology, while ensuring inclusion in diverse cultural and linguistic contexts.
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