Gold OA advantage is repeated at the discipline level
Differences are often found in the citing and downloading of articles in different disciplines and subject areas, so it is also important to consider reach and impact at a disciplinary level.22
The 204,781 articles in this study were associated with 33 different disciplines, and the disciplines varied considerably in size. The smallest category, Architecture / Design, contained just 14 articles, whereas the largest, Medicine and Public Health, contained 39,501 articles. In this section we consider the reach and impact of the 8 largest areas, each of which has over 10,000 articles. These are, in order from largest to smallest: Medicine and Public Health; Engineering; Life Sciences; Computer Science; Environment; Chemistry; Materials Science; and Biomedicine. We also consider 2 aggregated subject areas: the Humanities and Social Sciences.
In all 8 of the largest disciplines there is a consistent gold OA advantage, compared to both green OA and non-OA articles.
While there are discipline differences in the number and size of the gold OA advantage, in all 8 of the largest disciplines there is a consistent gold OA advantage, compared to both green OA and non-OA articles. This is both for citations and downloads. A similar citation and download advantage can also be seen for the Humanities and Social Sciences.
Gold OA download advantage up to nearly 10 times as high in certain disciplines
A clear gold OA advantage in the number of downloads an article receives can be seen over both green OA and non-OA across all the disciplines and subject areas considered.
The average size of the gold OA advantage in comparison to non-OA articles across the disciplines ranged from 5.42 times higher downloads (or 542%) in Biomedicine to 7.68 times higher downloads (or 768%) in Computer Science. The predicted advantage was even higher in Chemistry, however, with 9.61 times higher downloads (or 961%) for gold OA articles in comparison to non-OA articles.
The advantage for green OA over non-OA was far smaller, if not negligible or non-existent across the disciplines. In Medicine and Public Health, for example, the green OA articles received fewer downloads compared to non-OA, with only 0.94 times (94%) the number of downloads as a non-OA article. While the disadvantage disappeared in the predictive modelling, a similar sized disadvantage appeared in Materials Sciences (only 0.93 times (93%) the number of downloads). The biggest green OA advantage was found in the Life Sciences, both for the mean downloads (1.54 times higher) and the predicted downloads (1.61 times higher), although this is still far lower than the gold OA advantage.
The advantage for green OA over non-OA was far smaller, if not negligible or non-existent across the disciplines.
The subject areas of the Humanities and Social Sciences follow a similar pattern to the largest disciplines. In the Humanities, gold OA articles have 6.25 times higher downloads (or 625%) as non-OA articles (5.94 time higher predicted), and in the Social Sciences gold OA articles have 6.74 times higher downloads than non-OA articles (6.29 predicted). Caution should be taken when considering the green OA advantage, particularly with regards to the Humanities as there are only 47 green OA articles, however the smaller green OA advantage is in line with the 8 largest disciplines.
Table 6. Comparison of downloads across different disciplines and subject areas
|
Discipline or subject area |
Number of articles |
Non-OA |
Green OA |
Gold OA |
|||
|---|---|---|---|---|---|---|---|
|
Mean (%) |
Predicted (%) |
Mean (%) |
Predicted (%) |
Mean (%) |
Predicted (%) |
||
|
Medicine and Public Health |
39,501 |
100.00 |
100.00 |
93.60 |
104.79 |
589.50 |
703.63 |
|
Engineering |
21,891 |
100.00 |
100.00 |
150.54 |
114.11 |
679.48 |
646.15 |
|
Life Science |
20,875 |
100.00 |
100.00 |
153.62 |
161.36 |
560.61 |
764.65 |
|
Computer Science |
14,436 |
100.00 |
100.00 |
125.81 |
119.24 |
768.40 |
691.07 |
|
Environment |
13,864 |
100.00 |
100.00 |
139.31 |
150.83 |
674.02 |
741.91 |
|
Chemistry |
13,729 |
100.00 |
100.00 |
123.89 |
100.97 |
671.35 |
960.69 |
|
Materials Science |
11,806 |
100.00 |
100.00 |
115.82 |
93.18 |
589.58 |
584.20 |
|
Biomedicine |
10,795 |
100.00 |
100.00 |
138.71 |
162.97 |
542.08 |
758.00 |
|
Humanities |
3,424 |
100.00 |
100.00 |
99.71 |
103.07 |
624.92 |
593.63 |
|
Social Sciences |
21,045 |
100.00 |
100.00 |
112.32 |
114.46 |
674.23 |
628.66 |
Consistent gold OA citation advantage across disciplines
There are clear differences between the relative advantages of gold OA and green OA across the different disciplines and subject areas. For example, green OA articles underperform in some subject areas, with fewer citations compared to non-OA articles (e.g. Chemistry, Materials Science). The underlying message is evident: there is a clear and consistent citation advantage from publishing articles gold OA.
Of the 8 disciplines, the largest gold OA citation advantage is in Medicine and Public Health, where gold OA articles receive 1.94 times the number of citations as non-OA articles, and green OA articles only receive around half the number of citations as gold OA articles. Although the predictive model narrows the gap slightly between the 2 types of OA for Medicine and Public Health, there are still 1.90 times as many predicted citations for gold OA articles as non-OA articles and only 1.04 times as many predicted citations for green OA articles.
The largest predicted citations advantage for gold OA was in the discipline of Chemistry, where gold OA articles were predicted to have 4.11 times the number of citations as non-OA articles, and green OA articles were only predicted to have 0.91 times as many citations.
The underlying message is evident: there is a clear and consistent citation advantage from publishing articles gold OA.
The citation advantage for the Humanities and Social Sciences is in line with the 8 largest disciplines. Gold OA articles in the Humanities receive 1.58 times as many citations as non-OA articles (1.44 times predicted), and gold OA articles in Social Sciences receive 1.71 times as many citations (1.51 times predicted). While a slight citation advantage is found for green OA publications in Social Sciences (1.08 times as many citations), this disappears in the prediction model.
Table 7. Comparison of citations across different disciplines
|
Discipline or subject area |
Number of articles |
Non-OA |
Green OA |
Gold OA |
|||
|---|---|---|---|---|---|---|---|
|
Mean (%) |
Predicted (%) |
Mean (%) |
Predicted (%) |
Mean (%) |
Predicted (%) |
||
|
Medicine and Public Health |
39,501 |
100.00 |
100.00 |
98.53 |
103.61 |
193.97 |
190.15 |
|
Engineering |
21,891 |
100.00 |
100.00 |
110.92 |
96.27 |
127.79 |
144.39 |
|
Life Science |
20,875 |
100.00 |
100.00 |
137.49 |
216.16 |
158.04 |
235.13 |
|
Computer Science |
14,436 |
100.00 |
100.00 |
100.50 |
107.99 |
158.08 |
160.25 |
|
Environment |
13,864 |
100.00 |
100.00 |
115.13 |
174.32 |
151.48 |
195.03 |
|
Chemistry |
13,729 |
100.00 |
100.00 |
88.03 |
90.87 |
148.26 |
410.80 |
|
Materials Science |
11,806 |
100.00 |
100.00 |
80.21 |
69.79 |
137.68 |
132.83 |
|
Biomedicine |
10,795 |
100.00 |
100.00 |
126.58 |
188.81 |
184.08 |
210.92 |
|
Humanities |
3,424 |
100.00 |
100.00 |
93.17 |
98.85 |
158.49 |
143.83 |
|
Social Sciences |
21,045 |
100.00 |
100.00 |
108.41 |
95.01 |
171.03 |
151.01 |
22 Vaughan, L., Tang, J., & Yang, R. (2017). Investigating disciplinary differences in the relationships between citations and downloads. Scientometrics, 111(3), 1533–1545. https://doi.org/10.1007/s11192-017-2308-z
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