research output and transnational cooperation in physics subfields: a multidimensional analysis

Scientometrics, Vol. 31, No. 1 (1994) 97-122

R E S E A R C H O U T P U T A N D T R A N S N A T I O N A L

C O O P E R A T I O N IN P H Y S I C S S U B F I E L D S :

A M U L T I D I M E N S I O N A L A N A L Y S I S

P. S. NAGPAUL, LALITA SHARMA

National Institute o f Science, Technology and Development Studies Dr. K. S. Krishnan Mar~ New Delhi - 110 012 (India)

(Received January 17, 1994)

This paper compares the profiles of research output and transnational cooperation (as revealed through multicountry publications) of thirty six countries in ten subfields of Physics during the period 1981-1985. The data for comparative analysis were taken from Braun et al. 1 Since raw counts of publications are confounded by the size of the countries and the size of the research fields, this comparison is made, using relative indicators - activity index and collaboration index. The structures of research output and transnational cooperation are analyzed through Correspondence Analysis, which leads to the identification of countries with similar profiles (of research output and transnational cooperation) and the spatial representation of countries and Physics subfields. The configurations of research output and transnational cooperation are compared to assess the concordance between the policies of these countries for research and transnational cooperation in Physics.

Introduction

There are a variety of kinds and modes of cooperation between researchers and institutions of different countries. They include international meetings of experts, exchange of students and scientists, sharing of information, sharing of equipment and facilities, and direct transnational collaboration leading to coauthored research publications. However, as pointed out by Luukonen et al,2 not all collaborative efforts end up in coauthorships, nor all coauthored publications necessarily imply a close cooperation between the authors. But nonetheless, the writing of coauthored publications does indicate a fairly active linkage between researchers, closer and more active than the exchange of materials, information or sharing of research

facilities. There are a variety of factors, both internal and external to the scientific

enterprise, that stimulate international collaboration. The internal factors are cognitive and social, whereas the external factors are economic and political. The

Scientometrics 31 (1994) Elsevier, Amsterdam - Oxford - New York - Tokyo

Akad~miai Kiad6, Budapest

P. S. NAGPAUL, L. SHARMA: RESEARCH OUTPUT AND COOPERATION IN PHYSICS

latter include easier and less expensive communication, governmental initiatives to increase international contacts through travel grants and bilateral and multilateral agreements between countries and initiatives of international agencies (e.g. UNESCO, UNDP, WHO, etc.).

Transnational cooperation is becoming more frequent and is playing a more important role in the production of scientific knowledge. An indicator of this trend is the substantial increase in the proportion of research publications, cosigned by authors from two or more countries. The number of multicountry publications has arisen from 3.7% in 1973 to an estimate of 10.3% in 1990, which amounts to annual growth rate of about 7 - 8% over the period. 3

A recent study by Narin et al,4 indicates that multicountry publications receive more citations than single-country publications. Hence, it can be assumed that multicountry publications constitute a more important segment of the world literature in science than single-country publications. Their importance can also be gauged from the fact that bibliometric data on multicountry publications have received the attention of science policy institutions 5 and researchers 6 in several countries.

This paper seeks to examine the patterns of publication output and internationally coauthored publications in different subfields of Physics. Its main concerns are: (i) Which are the areas of Physics that have received greater priority in research

and transnational cooperation than others? Do the priorities for research and transnational cooperation match with each other?

(ii) Which are the areas of research priority and transnational cooperation of different countries and how do they match with each other?

(iii) Can we classify the countries into typologies based on their patterns of research output and transnational cooperation? Do these two typologies match with each other?

Methodology and data

The data for this study were taken from Braun et al.7 They examined the pattern and strength of linkages among thirty six countries separately for each subfield of Physics, using Salton's measure of linkage. 8 The present study, which is complementay to Braun et al. has a different objective and adopts a different statistical methodology (viz. Correspondence Analysis). 9 Using the data on internationally coauthored publications (for five years: 1981-1985), it analyses the

98 $cientometrics 31 (1994)


multidimensional structure of relationships of these countries with Physics subfields through Correspondence Analysis. It also compares the multidimensional structure of transnational cooperation with that of publication output of these countries in different subfields.

General overview of the data

Transnational cooperation in Physics subfields

Table 1 presents the data on publication output and internationally coauthored publications (ICOP's) in different subfields of Physics. The names of these subfields and their abbreviations are also given in the table, which indicates wide variations in the number of publications in different subfields as well as in the percentage of ICOP's. Applied Physics is the largest subfield, but the percentage of ICOP's is quite low (only 9.15%). Nuclear Physics and Particle Physics are the most important subfields for transnational cooperation. More than 30% of publications in these subfields involve international coauthorship. Acoustics is the least important subfield for transnational cooperation; only 7.5% of publications in this subfield are internationally coauthored.

Table 1

Research output and co-authored publications in different subfields of Physics

Subfield Abbreviation No. of ICOP's Publications No. Percentage

Fluids & Plasmas Flu 6824 955 13.98 Condensed Matter Cond 44588 8807 19.75 Chemical Physics Chem 36674 7346 20.03 Applied Physics App 50188 4592 9.15 Nuclear Physics Nucl 21217 6386 30.10 Particle Physics Part 13524 4423 32.66 Mathematical Physics Math 5338 1207 22.61 Optics Opt 15869 1426 8.99 Mechanics Mech 12387 1420 11.46 Acoustics Acus 10635 800 7.52

Total 217279 37362 17.20

Scientometrics 31 (1994) 99


Status of Physics in transnational cooperation

Table 2 present the data on publication output and internationally coauthored publications (ICOP's) of thirty six countries, rank ordered according to the number of papers published in Physics. The names of these countries and their ISO trilateral codes are given in the table. Benchmark data on the percentage of ICOP's in science as a whole (i.e. all fields combined together) are also presented for assessing the

status of Physics in transnational cooperation. The benchmark data indicate wide variations in the level of transnational

cooperation in science. USSR is the most isolated country, with less than 3% of its publications involving international coauthorship. On the other hand, Mexico has the highest level of transnational cooperation in science; more than 25% of its publications involve international coauthorship.

In all these countries the level of transnational cooperation in Physics is consistently higher than that in science. However, the difference between these two indicators varies considerably across the countries, implying differences in the priority accorded to Physics in transnational cooperation. To examine these differences rather more systematically, we construct an index - Cooperation Preference Index (CPI), which compares the standing of different countries on the basis of their transnational cooperation in Physics relative to that in all science fields combined together. CPI is computed by the following formula:

CPI = Worm share of ICOP's in Physics

World share of ICOP's in all science fields

The values of CPI given in Table 2 indicate that there are major differences in the priority accorded to Physics in transnational cooperation. Denmark (CPI = 3.34) outranks all other countries on this indicator, whereas China has the lowest rank (CPI = 1.27). China and Hungary have the same level of transnational cooperation in science (about 17% ICOP's), but the values of CPI are quite different (China: 1.27; Hungary: 2.15), implying that China accords less priority to Physics compared with Hungary.

100 S cientometrics 31 (1994)


Table 2

Research output and co-authored publications in Physics

Country ISO Code No. of ICOP's (Physics) ICOP's CPI publications (all fields)

Number Percentage Percentage

USA USA 73228 8423 11.50 6.0 1.92 USSR SUN 24905 1107 4.44 2.9 1-53 Germany (FR) DEU 16654 4156 24.95 12.8 1.95 Japan JPN 16432 1152 7.01 5.2 1.35 U.K. UKD 14983 3192 21.30 10.5 2.03 France FRA 12409 3353 27.02 14A 1.88 Canada CAN 7402 1803 24.36 14.0 1.74 India IND 5897 595 10.09 6.1 1.65 Italy ITA 5659 1598 28.24 14.6 1.93 Switzerland CHE 3909 1849 47.30 21.4 2.21 Netherlands NLD 3683 886 24.06 14.8 1.62 Poland POL 3444 822 23.80 16.9 1.32 Israel ISR 3091 1004 32.48 19.0 1.71 Australia AUS 3061 507 16.56 11.0 1.51 Germany (East) DDR 2406 551 22.90 12.7 1.80 Sweden SWE 2187 768 35.12 16.7 2.10 Belgium BEL 2112 707 33.48 18.7 1.79 Spain ESP 1765 386 21.87 113 1.90 China PRC 1561 345 22.10 17.4 1.27 Brazil BRA 1373 372 27.09 18.6 1.46 Czechoslovakia CSK 1250 345 27.60 13.0 2.12 Austria AUT 1210 417 34.46 15.7 2.19 Denmark DNK 1124 721 64.15 19.2 3.34 Finland FIN 974 277 28.44 13.8 2.06 Yugoslavia YUG 848 303 35.73 20.2 1.77 Hungary HUN 845 313 37.04 17.2 2.15 Argentina ARG 719 112 15.58 8.8 1.77 Greece GRC 704 200 28.41 19.9 1.61 Bulgaria BGR 680 168 24.71 17.7 1.40 Norway NOR 636 253 39.78 17.1 2.33 Mexico MEX 591 225 38.07 25.2 1.51 South Africa ZAF 441 130 29.48 10.0 2.95 New Zealand NZL 375 98 26.13 11.7 2.23 Egypt EGY 334 83 24.85 18.2 1.36 Ireland IRL 281 112 39.86 15.8 2-52 Chile CHL 106 29 27.36 12.3 2.22



Transnational cooperation of different countries

During the five-year period 1981-1985, these countries published 217,272 papers in Physics. Of these, 37,362 papers had involved international coauthorship',

constituting about 17.2% of all papers in this field. The top eight countries account for 79.1% of all publications and 63.6% of all ICOP's in Physics.

It can be easily seen from the table that there are wide variations in the proportion of ICOP's among the countries. Notwithstanding certain notable exceptions, smaller (in scientific size) countries have shown greater propensity for transnational cooperation than the larger ones. As pointed out by Narin, 11 this is a

direct consequence of the scientific size. Scientists in small countries such as Denmark have more potential collaborators outside their own countries than within their own countries, but reverse is the case for large countries such as USA.

Denmark which ranks 23rd in publication output has the highest incidence of ICPO's (64%), followed by Switzerland which ranks 10th in publication output; it has the next highest incidence of ICOP's (about 47%). USSR is the most isolated country in the world; it has the lowest incidence of ICOP's (4.4%).

The proportion of ICOP's as an indicator of transnational cooperation has a limitation; there is no benchmark or standard to judge its value. We therefore define an index - Relative Cooperation Index (RCI) - which is computed as follows:

R C / = World share of ICOP's

World share of publications

This index compares the standing of different countries on the basis of their transnational cooperation relative to that for all these countries combined together.

RCI is best visualized through a relational chart (Fig. 1), wherein the position of a country above the main diagonal indicates more than average level of cooperation, while the position of a country below the main diagonal implies less than average

level of cooperation. It can be easily seen from Fig. 1 that almost all the countries which account for less than 2% of publications in Physics are situated above the main

diagonal. They have more ICOP's than expected on the basis of their publications in

Physics. In contrast, large countries such as USA, USSR, India and Japan situated below the main diagonal have less than average level of transnational cooperation than the remaining countries.

102 Sciemometrics 31 (1994)

40 o o

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c

10

P. S. NAGPAUL, L. SHARMA: R E S E A R C H O U T P U T AND C O O P E R A T I O N IN PHYSICS

oV" i 0 10 20 30 40

Percentage of papers

I M V

R G

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Percentage of papers

A SUN S BRA B JPN T CHL C IND U CSK D USA V ITA E A R G W GR C F AUS X FIN G UKD Y Z AF tt ESP Z ISR I PRC a BEL J POL b A U T K D D R c SWE L NDL d Y U G M CAN e H U N N B G R f MEX O EGY g N O R P DEU h IRL Q NZL i CHE R FRA j DNK

2.0

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~ ~xU/ 1.0- a i ' /

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Fig. 1. Relational chart

The scatter of the countries about the main diagonal indicates that the country size is not the sole explanatory variable of international coauthorship; it is one of them. For example, Japan and FRG have about the same number of publications, but the percentage of ICOP's in these two countries is markedly different (7.01% for Japan; 24.95% for FRG). It appears that besides size, many other factors influence the propensity of countries to collaborate internationally. These factors might include the language barrier, geographical distance and socio-cultural and political proximity. 12



Publication outPut in different subfields

Table 3 presents the distribution of publications of these countries in different subfields of Physics. It can be easily seen from the table that there are wide variations

in the distribution of publications among these countries. However, we can not comprehend these differences because the raw publication counts are confounded by the size of the countries as well as by the size of the subject fields. It is therefore

necessary to translate the raw data on publication counts into an index, wherein the

effect of confounding factors is eliminated. Hence, an index, called Activity Index (AD, was computed. Activity Index was first proposed by Frame 13 and was used among others by Schubert and Braun, 14 Carpenter et al.15 and Na ~a u l and Pant. 16 ,41

is computed as follows:

(aOij = [(nij/n o) / (noj/noo)l x loo

where nij is the number of publications of country i in subfield j;

nio is the number of publications of country i in all subfields; noj is the number of publications of all countries in subfield j; noo is the total number of publications of all countries in all subfields.

Here 'all' refers to the comparison set (i.e. the set of thirty six countries). The activity index has an important advantage over raw publication counts in that

it inherently takes into account both the size of the country and the size of the subject area. A high degree of relative emphasis in a large subfield, such as Condensed Matter, would require far more publications than a small subfield such as Fluids &

Plasmas. A / > 100 for a subfield indicates that a country publishes more papers in the subfield in relation to its total output than average for that subfield, and vice

versa. A I can be used for comparing the publication output of different research

fields within a country or that of different countries for a given research field.

104 S cientometrics 31 (1994)

P. S. NAGPAUL, L. SHARMA: R E S E AR C H O U T P U T AND C O O P E R A T I O N IN PHYSICS

Table 3

Publication output of different countries in Physics subfields

Country Flu Cond Chem AppI Nucl Part Math Optc Mech Acus

USA 3506 9927 13028 17780 5432 4001 2034 7390 4769 5361 SUN 297 9330 1292 7221 2380 2135 181 388 1015 666 D E U 321 4000 3280 2414 3017 1022 355 1082 719 444 JPN 433 2356 1921 7752 1029 442 168 1037 668 626 U K D 660 2504 3421 3055 1105 823 232 1055 1282 846 FRA 236 2954 2234 2602 1363 675 450 988 568 339 CAN 175 1093 1896 1229 828 393 249 568 547 424 IND 131 1791 873 1004 436 339 145 299 553 326 VIA 120 978 1117 929 587 899 236 447 203 143 CHE 66 818 701 447 702 781 120 149 59 66 NLD 80 705 875 647 510 176 104 222 150 214 POL 20 1189 550 512 311 164 92 250 284 72 ISR 85 560 758 569 271 184 83 257 195 129 AUS 187 279 665 525 342 71 91 308 357 236 D D R 100 1328 236 246 195 67 18 153 50 13 SWE 94 444 479 307 372 120 38 120 87 126 BEL 28 453 481 254 380 157 146 78 63 72 ESP 26 467 370 302 109 181 109 176 25 0 PRC 32 310 347 180 365 121 28 46 57 75 BRA 24 570 188 153 161 119 66 62 30 0 CSK 14 409 158 395 81 30 29 59 52 23 A U T 23 268 222 256 126 100 49 41 75 15 DNK 32 195 65 279 116 66 23 155 133 60 FIN 4 199 157 213 185 71 21 60 16 48 Y U G 8 258 192 93 140 63 11 35 27 21 H U N 8 201 176 171 160 31 15 43 27 13 A R G 0 132 167 65 134 37 31 60 16 77 G R C 10 166 97 63 53 83 31 25 134 42 B G R 18 204 138 143 43 14 19 74 20 7 N O R 30 57 222 52 52 54 12 60 42 55 MEX 5 135 118 87 47 53 67 56 18 5 ZAF 16 81 56 80 110 12 23 11 32 20 NZL 17 58 82 31 30 5 13 52 45 42 EGY 7 102 30 67 32 2 2 27 46 19 IRL 6 39 58 51 9 19 34 36 19 10 CHL 5 28 24 14 4 14 13 0 4 0

Scientometrics 31 (1994) t 0 5


Table 4

Activity profiles of different countries

Country Flu Cond Chem App Nucl Part Math Opt Mech Acus

USA 152 66 105 105 76 77 113 138 114 150 SUN 38 183 31 126 98 122 30 21 71 55 DEU 61 117 117 63 186 87 87 89 76 54 JPN 84 70 69 204 64 38 42 86 71 78 UKD 140 81 135 88 76 78 63 96 150 115 FRA 61 116 107 91 112 77 148 109 80 56 CAN 75 72 152 72 115 75 137 105 130 117 IND 71 148 88 74 76 82 100 69 164 113 1TA 68 84 117 71 106 225 170 108 63 52 CHE 54 102 106 50 184 283 125 52 26 34 NLD 69 93 141 76 142 68 115 83 71 119 POL 18 168 95 64 92 68 109 99 145 43 ISR 88 88 145 80 90 84 109 114 111 85 AUS 195 44 129 74 114 33 121 138 205 158 DDR 132 269 58 44 83 39 30 87 36 11 SWE 137 99 130 61 174 78 71 75 70 118 BEL 42 105 135 52 184 105 281 51 52 70 ESP 47 129 124 74 63 145 251 137 25 0 PRC 65 97 132 50 239 110 73 40 64 98 BRA 56 202 81 48 120 123 196 62 38 0 CSK 36 159 75 137 66 34 94 65 73 38 AUT 61 108 109 92 107 117 165 46 109 25 DNK 91 85 34 107 106 83 83 189 208 109 FIN 13 100 95 95 195 103 88 84 29 101 YUG 30 148 134 47 169 105 53 57 56 51 HUN 30 116 123 88 194 52 72 70 56 31 ARG 0 89 138 39 191 73 175 114 39 219 GRC 45 115 82 39 77 167 179 49 334 122 BGR 84 146 120 91 65 29 114 149 52 21 NOR 150 44 207 35 84 120 77 129 116 177 MEX 27 111 118 64 81 127 461 130 53 17 ZAF 116 90 75 79 255 39 212 34 127 93 NZL 144 75 130 36 82 19 141 190 210 229 EGY 67 149 53 87 98 8 24 111 242 116 IRL 68 68 122 79 33 96 493 175 119 73 CHL 150 129 134 57 39 187 499 0 66 0

The values of activity index for different subfields are presented in Table 4, which shows differences in disciplinary emphasis among the countries. It can be easily seen for example that India has published more papers in Applied Physics than in Mechanics, but it has higher activity in Mechanics (AI = 164) than in Applied Physics ( A / = 74). India has 64% more publications in Mechanics and 26% less publications

106 Scientometrics 31 (1994)


in Applied Physics than expected on the basis of its total output in Physics.

Switzerland ( A / = 283) and Italy (AI = 225) have given the highest priority to

Particle Physics, whereas Japan (AI = 38) has given the lowest priority to this

subfield.

Output of internationally coauthored publications

Table 5 presents the data on the ICOP's of different countries in various subfields

of Physics. It can be easily seen that there are wide variations in the distribution of

ICOP's in different subfields among the countries. However, we cannot comprehend

these differences because the raw counts of ICOP's are confounded by the size of the

countries and the size of the subfields as measured by the number of ICOP's. For instance, India has more ICOP's in Applied Physics than in Mechanics but this does

not mean that India has greater transnational cooperation in Applied Physics. As we

shall see later, the situation is just the reverse.

Hence, we compute an index, called Collaboration Index (CO, which eliminates the effect of confounding factors cited above. This index is computed in the same

manner as activity index. Table 6 presents the values of CI for different subfields. It

can be easily seen from the table that India collaborates more in Acoustics (CI = 220) than in Nuclear Physics (CI = 54). India had 120% more ICOP's in

Acoustics and 46% less ICOP's in Nuclear Physics than the expected level. It may be

recalled that Acoustics is the least preferred subfield for transnational cooperation

(see Table 1). Again, India collaborates more in Mechanics (CI--230) than in

Applied Physics (CI = 107). In the area of Nuclear Physics, FRG (CI = 137)

collaborates more than India (CI = 54). FRG had 37% more ICOP's and India has

46% less ICOP's in this subfield than the expected levels.

We can also compare the values of AI and CI for a given country. For example, in

the area of Fluids and Plasmas, India had less than average level of activity (AI = 71)

but more than average level of collaboration (CI = 152).

Scientornetrics 31 (1994) 107


Table 5

Internationally co-authored publications of different countries in Physics subfields


USA 259 1787 1655 1120 1293 840 348 370 467 284 DEU 82 996 876 456 974 450 94 115 77 36 FRA 44 939 603 435 622 361 128 139 48 34 UKD 127 671 705 422 333 430 65 119 213 107 CHE 15 388 249 118 422 541 53 38 14 I1 CAN 46 312 472 232 340 120 53 87 99 42 ITA 27 330 284 156 218 388 68 83 32 12 JPN 50 285 173 225 170 103 27 25 58 36 SUN 44 420 96 152 179 147 18 35 11 5 ISR 29 205 266 112 117 112 41 44 49 29 NLD 20 223 191 99 171 102 24 33 12 11 POL 4 275 169 76 121 103 16 31 22 5

S W E 29 176 193 73 167 59 9 26 U 25 DNK 9 165 159 73 210 72 10 9 9 5 BEL 7 169 156 75 145 86 39 17 8 5 IND 20 149 122 78 55 43 20 28 52 28 DDR 21 282 69 57 63 40 3 13 2 1 AUS 33 54 127 56 80 23 26 25 59 24 AUT 11 111 65 75 57 52 13 10 19 4 ESP 3 111 68 53 50 50 21 23 7 0 BRA 9 129 63 41 56 35 18 10 11 0 CSK 3 118 54 88 43 13 9 8 7 2 PRC 19 45 19 53 49 40 11 29 51 29 HUN 4 83 60 47 82 I2 5 16 2 2 YUG 3 78 67 21 81 36 3 4 6 4 FIN 2 56 35 42 62 42 13 17 3 5 NOR 7 21 100 12 37 34 10 7 8 17 MEX 1 65 55 34 25 11 17 14 2 1 GRC 1 40 45 11 25 44 8 2 19 5 BGR 9 42 38 31 19 10 3 11 4 1 ZAF 6 17 18 15 48 7 7 1 8 3 ARG 0 12 25 10 43 8 3 3 1 7 IRL 3 23 25 24 6 3 10 14 2 2 NZL 6 7 19 6 13 2 9 12 12 12 EGY 1 17 16 11 8 1 1 8 14 6 CHL 1 6 9 3 2 3 4 0 1 0

108 ".. Scientometrics 31 (1994)

P. S. NAGPAUL, L. SHARMA: R E S E A R C H O U T P U T AND C O O P E R A T I O N IN PHYSICS

Table 6

Co-authorship profiles of different countries


USA 120 90 100 108 90 84 128 115 146 157 D E U 77 102 107 89 137 91 70 72 49 40 FRA 51 119 91 106 109 91 118 109 38 47 U K D 156 89 112 108 61 114 63 98 176 157 CHE 32 89 68 52 134 247 89 54 20 28 CAN 100 73 133 105 110 56 91 126 144 109 ITA 66 88 90 79 80 205 132 136 53 35 JPN 170 105 76 159 86 76 73 57 132 146 SUN 156 161 44 112 95 112 50 83 26 21 ISR 113 87 135 91 68 94 126 115 128 135 NLD 88 107 110 91 113 97 84 98 36 58 POL 19 142 105 75 86 106 60 99 70 28 SWE 148 97 128 77 127 65 36 89 38 152 DNK 49 97 112 82 170 84 43 33 33 32 BEL 39 101 112 86 120 103 171 63 30 33 IND 132 106 104 107 54 61 104 123 230 220 D D R 149 217 64 84 67 61 17 62 10 08 AUS 255 45 127 90 92 38 159 129 306 221 A U T 103 113 79 146 80 105 97 63 120 45 ESP 30 122 90 112 76 109 168 156 48 0 BRA 95 147 86 90 88 79 150 70 78 0 CSK 34 145 80 208 73 32 81 61 53 27 PRC 215 55 28 125 83 98 99 220 389 393 H U N 50 112 97 122 153 32 49 134 17 30 YUG 39 109 112 56 156 100 31 35 52 62 FIN 28 86 64 123 131 128 145 161 28 84 N O R 108 35 201 39 86 114 122 72 83 314 MEX 17 123 124 123 65 41 234 163 23 21 GRC 20 85 114 45 73 186 124 26 250 117 B G R 210 106 115 150 66 50 55 172 63 28 ZAF 181 55 70 94 216 45 167 20 162 108 A R G 0 45 114 73 225 60 83 70 23 292 IRL 105 87 114 174 31 23 276 328 47 83 NZL 240 30 99 50 78 17 284 321 322 572 EGY 47 87 98 108 56 10 37 253 444 338 Ct tL 135 88 158 84 40 87 427 0 91 0

Structure of research output

T h e s t r u c t u r e o f m u l t i v a r i a t e r e l a t i o n s h i p s b e t w e e n t h e s e t o f 36 c o u n t r i e s a n d t e n

s u b f i e l d s o f P h y s i c s w a s a n a l y z e d t h r o u g h C o r r e s p o n d e n c e A n a l y s i s , u s i n g t h e

c o m p u t e r p r o g r a m C O R A N (Lebart, Morineau a n d Warwick). 17 T h i r t e e n c o u n t r i e s ,


P. S. NAGPAUL, L. SHARMA: RF~SEARCH OUTPUT AND COOPERATION IN PHYSICS

which had less than 1,000 publications in Physics, were treated as supplementary variables in the analysis. 18 Supplementary variables do not influence the

determination of factorial axes, but their coordinates and squared correlations

(relative contributions) are computed. As a result of correspondence analysis, each subfield in the high-dimensional space is projected into the low-dimensional subspace

of 36 countries, whereas each country is projected into the conjugate subspace of ten subfields.

The eigen values of different factorial axes computed by the program indicate that

the fhrst three axes, accounting for about 85.4% of the total variance yield the most parsimonious representation of the multidimensional data. The remaining axes, accounting for smaller amounts of variances, represent information of idiosyncratic nature, which does not have much bearing on the basic structure of multivariate relationships.

Figure 2 represents a two-dimensional factorial map constituted by ~1 and tI' 2 axes. These two axes account for 76.2% of the total variance; the third factorial axis accounts for 9.2% of the total variance. Thus, the tw0-dimensional factorial map reveals the main features of the multidimensional data. The third factorial axis, q~3, represents complementary data for further analysis. It is necessary to consider the third axis, since some of the subfields and countries are poorly represented in the two-dimensional factorial map as revealed by the values of cos2qb.

Some keys for interpreting the factorial map are:

(i) The barycentre located at the origin of the axes corresponds to the average

profdes of both sets of points (i.e. subfields and countries). Closer a country to the orighl, better balanced it is in every field. On the contrary, closer a country to the edge of the map, more specialized that country is in a certain subfield.

Similarly, closer a subfield to the edge of the map, more specific it is to a certain country (located in its neighbourhood). The location of a subfield close to the origin indicates that every country is giving about the same priority to that subfield.

(ii) Two elements of a given space (for example, two countries) are all the more interrelated to the conjugate space (i.e. subfields) as they are near one another

and far from the origin i.e. they have similar profiles. On the other hand,

greater the distance between these points, more different are their profiles. The same relationship also holds true for two subfields.

110 Scientomelrics 31. (1994)

P. S. N A G P A U L , L. S H A R M A : R E S E A R C H O U T P U T A N D C O O P E R A T I O N IN P H Y S I C S

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Scientometrics 31 (1994) 1 1 1


(iii) Two elements belonging to different spaces (countries and fields) are all the

more interrelated as they are near each other and far from the origin.

Elements far from each other have little or no relationship. However,

additional examination of theoretical parameters (viz. absolute contribution,

AC; relative contribution, RC) is required to validate such relationships.

It can be easily seen from the factorial map that none of the subfields or countries

are located near the barycentre, indicating speciticities of their profiles.

Factor r The first factor, which accounts for 46.2% of the total variance, is the

most important element of the structure of multivariate relationships between

countries and Physics subfields.

On the cloud of subfields, this factor is controlled by Condensed Matter

(AC = 51.6%; RC = 0.91), Acoustics (AC = 9.6% RC = 0.71), Fluids & Plasmas

(AC = 6.6%, RC = 0.69), Optics (AC = 11.6%; RC = 0.76)), Chemical Physics

(AC = 10.5%; RC = 0.44) and Mechanics (AC = 3.3%; RC = 0.35).

Condensed Matter is projected on this axis with positive coordinate. Acoustics,

Fluids & Plasmas, Optics, Chemical Physics and Mechanics, having negative

coordinates on this axis, are associated. These subfields are opposed to Condensed

Matter.

These results imply that the countries which emphasize Condensed Matter tend

to de-emphasize Fluids & Plasmas, Acoustics, Optics and Chemical Physics, and vice versa.

On the country cloud, this axis is controlled by USA (AC = 26.7%; RC = 0.89),

USSR (AC = 45.6%; RC = 0.85), UK (AC = 2.6%; RC = 0.42), Poland

(AC = 1.8%; RC = 0.43), Australia (AC = 3.2%; RC = 0.67), GDR (AC = 7.3%;

RC = 0.59) and Brazil (AC = 2.6%; RC = 0.69). All these countries are represented

better on this axis than on any other axis. Other countries that contribute to this axis,

but are not best represented on this axis, are: Canada (AC = 1.5%; RC = 0.32) and

India (AC = 1.1%; RC0.26). Czechoslovakia does not contribute much to the

composition of this factor, but is better represented on this axis than on any other

ards (AC = 0.7%; RC = 0.45). Among the countries that were treated as

supplementary variables in the analysis, Yugoslavia (RC= 0.36), Norway

(RC = 0.40) and New Zealand (RC = 0.40) are also represented on this axis.

USA, UK, Canada, Australia, Norway and New Zealand are projected on this

axis with negative coordinates. These countries are correlated to Fluids & Plasmas,

Acoustics, Mechanics, Optics and Chemical Physics. They are anticorrelated to

112 $cientometrics 31 (1994)


Condensed Matter. Canada is situated around the pole of Chemical Physics, implying Canada's strong commitment to this subfield.

USSR, India, Poland, GDR, Brazil, Czechoslovakia and Yugoslavia have positive coordinates on this axis. They are correlated to Condensed Matter and anticorrelated to Fluids & Plasmas, Acoustics, Mechanics, Optics and Chemical Physics. USSR and

G D R are situated around the pole of Condensed Matter, implying their strong emphasis on this subfield.

Factor 02: Tiffs factorial axis accounts for 30.0% of the total variance in the

multidimensional data. On the cloud of subfields, this axis is controlled by Applied Physics (AC = 60.6%; RC -- 0.93), Chemical Physics (AC = 15.9%; RC = 0.43), Nuclear Physics (AC = 3.8%; RC -- 0.47) and Mathematical Physics (AC = 3.8%; RC = 0.35). Applied Physics, which is projected on this axis with positive coordinate, is opposed to Nuclear Physics, Chemical Physics and Mathematical Physics, which are projected on this axis with negative coordinates. However, it is necessary to point

out that opposition along the second factorial axis is less pronounced than that on the first axis, since the second axis explains less variance than the first axis.

On the country cloud, this factor is controlled by Japan (AC = 45.6%; RC = 0.85), FRG (AC = 23.9%; RC = 0.54), Italy (AC = 4.1%; RC 0.33), Canada (AC3.52%; RC = 0.47), Switzerland (AC = 7.6%; RC = 0.38), the Netherlands (AC = 1.5%; RC = 0.51), Poland (AC = 1.7%; RC = 0.41), Sweden (AC = 1.6%;

RC = 0.56), Belgium (AC = 3.5%; RC = 0.59) and China (AC = 2.6%; RC = 0.53). Israel (RC = 0.41) which contributes less than 1% variance to the composition of

this factorial axis, is represented better on this axis than on any other axis. Yugoslavia

(RC = 0.48), Argentina (RC = 0.49) and Norway (RC = 0.40) which were treated as supplementary variables are also represented on this axis.

Japan, having positive coordinate on this axis, is correlated to Applied Physics and anticorrelated to Chemical Physics, Nuclear Physics and Mathematical Physics. FRG, Canada, Italy, Switzerland, the Netherlands, Poland, Sweden, Belgium, China,

Yugoslavia, Argentina, Norway and Israel have negative coordinates on this axis.

These countries are associated and correlated to Chemical Physics, Nuclear Physics and/or Mathematical Physics.

Factor 03: The third factorial axis accounts for about 9.2% of the total variance of

the multidimensional data. Figure 3 represents the main relationships between countries and subfields in the form of a vertical scale (one-dimensional representation).



O6

CHE EGY

0.3- ITA

FIN

JPN NUCL APP

COND

MECH IND POL

-O:

-0.6 -

NZL

DDR

Fig. 3. Positioning of significant countries and subfields on factorial axis dP 3 (publication output)

On the cloud of subfields, this factor is mainly composed of Condensed Matter (AC = 23.0%), Applied Physics (AC = 12.2%), Nuclear Physics (AC = 11.7%), Particle Physics (AC = 26.0%) and Mechanics (AC = 15.9%). Condensed Matter and Mechanics are projected on this axis with negative coordinates, opposing Applied Physics, Nuclear Physics and Particle Physics, which are projected on this axis with positive coordinates.

On the country cloud, this factor is constituted by Japan (AC = 14.5%), India (AC = 10.5%), Italy (AC = 13.4%), Switzerland (AC = 22.9%), Poland

(AC = 6.2%) and GDR (AC = 17.5%). India is represented better on this axis (RC = 0.50) than on the first two axes. Among the countries that were treated as supplementary variables, Finland (RC = 0.31), New Zealand (RC = 0.37) and Egypt (RC -- 0.58) are represented better on this axis than on any other axis.


P. S. NAGPAUL, L. SHARMA: RESEARCH OUTPLVI" AND COOPERATIGN IN PHYSICS

Japan, Italy, Switzerland and Finland, having positive coordinates on this axis, are associated and correlated to Applied Physics, Nuclear Physics and Particle Physics.

India, Poland, GDR, New Zealand and Egypt, having negative coordinates on this

axis, are associated and correlated to Condensed Matter and Mechanics.

Structure of transnational cooperation

The multivariate structure of transnational cooperation of 36 countries was

analyzed through Correspondence Analysis, using the Computer Program CORAN.

Thirteen countries, which had less than 1000 publications in Physics were treated as

supplementary variables in the analysis. The eigen values of different factorial axes computed by the program indicate that

the first three axes, accounting for about 83.6% of the total variance, yield the most parsimonious representation of the multidimensional data. The remaining factorial

axes represent smaller amounts of information, which have less bearing oil the basic

structure of the multidimensional data. Figure 4 represents the two-dimensional factorial map constituted by ~1 and qb 2

axes. These two axes account for 68.2% of the total variance of the multidimensional

system. Factor Cbl: The first factorial axis, accounting for 45.4% of the total variance, is

the most important element of the multivariate relationships between ~% countries

and ten subfields of Physics. On the cloud of subfields, this factor is controlled by Mechanics (AC = 33.5%;

RC = 0.88), Fluids & Plasmas (AC = 6.7%; RC = 0.57), Acoustics (AC = 12.9%;

RC = 0.83), Optics (AC = 2.2%; RC = 0.33), Applied Physics (AC = 3.6%;

RC = 0.28), Particle Physics (AC = 18.6%; RC = 0.37), Nuclear Physics

(AC = 7.6%; RC = 0.32) and Condensed Matter (AC = 7.1%; RC = 0.24). Particle Physics, Nuclear Physics and Condensed Matter having positive

coordinates on this axis are associated; they are opposed to Fluids & Plasmas,

Acoustics, Mechanics, Optics and Applied Physics which have positive coordinates on

this axis. These results imply that the countries which give higher priority in

international collaboration to Fluids & Plasmas, Acoustics, Mechanics, Optics and

Applied Physics tend to give lower priority to Particle Physics, Nuclear Physics and

Condensed Matter and vice versa.


P. S. N A G P A U L , L. S H A R M A : R E S E A R C H O U T P U T A N D C O O P E R A T I O N IN P H Y S I C S

W I

(3.. < I . - -

Z

b_

z

Z

~ o ~/

Z

I

LL/.

Z m

k)

~ 0

iv0 o

-t

,, ,~t , , , , I I ~_

~ ~ - - - . o o o o o o ; . ~ ~ ~ '~, o o o o o 0 0 o o o o o o o o o o o o 0 0 0 0 0 0 0 0 o o

i i i f i i i i i i i i i f i i



On the country cloud, this factor is constituted by USA (AC = 17.0; RC 0.89),

FRG (AC = 5.4; RC = 0.41), France (AC --- 3.8%; RC = 0.47), U.K. (AC = 7.1;

RC = 0.50), Switzerland (AC = 24.4%; RC = 0.59), Canada (AC = 3.4; RC = 0.41),

Italy (AC = 4.9; RC = 0.30), Japan (AC = 1.5; RC = 0.24), USSR (AC = 3.8;

RC = 0.29), Israel (AC = 1.4; RC ~ 0.39), the Netherlands (AC = 0.8; RC = 0.53),

Poland (AC = 2.2; RC = 0.30), China (AC = 8.5; RC = 0.54), Denmark

(AC = 2.1%; RC = 0.30), Belgium (AC = 1.3%; RC = 0.41) and India (AC = 4.5;

RC = 0.81).

USA, UK, Canada, China, Japan, Israel and India are projected on this axis with

negative coordinates. New Zealand (RC = 0.63) and Egypt (RC = 0.70) which are

treated as supplementary variables in the correspondence analysis are also

represented on this axis with negative coordinates. All these countries are associated

with Mechanics, Acoustics, Optics, Applied Physics and Fluids & Plasmas in

transnational cooperation.

FRG, France, Switzerland, Italy, USSR, the Netherlands, Poland and Denmark

are projected on this axis with positive coordinates. Yugoslavia (RC = 0.37), a

supplementary variable in the analysis is also represented on this axis with positive

coordinate. All these countries are associated with Particle Physics, Nuclear Physics

and Condensed Matter.

Factor ~2: The second factorial axis accounts for 22.8% of the total variance in

the multidimensional data.

On the cloud of subfields, this factor is controlled by Condensed Matter

(AC = 28.8%; RC = 0.48) and Particle Physics (AC = 56.3%; RC = 0.56). Particle

Physics, projected on this axis with positive coordinate is opposed to Condensed

Matter, which is projected on this axis with negative coordinate. However, the

opposition along ~2 axis is less strong than on ~1 axis, since the former accounts for

less variance than the latter.

On the country cloud, this factor is controlled by Italy (AC = 17.2%; RC = 0.50),

France (AC = 0.49%; RC = 0.30), Switzerland (AC = 31.6%; RC = 0.38), GDR

(AC = 14.5%; RC = 0.48), Brazil (AC = 1.6%; RC = 0.38) and Czechoslovakia

( A c = 7.2%; RC = 0.58).

Italy and Switzerland having positive coordinates on this axis are associated.

Greece (RC = 0.51), which is treated as a supplementary variable is also represented

on this axis. Thus, these three countries are correlated to Particle Physics.

France, GDR, Brazil, Czechoslovakia are projected on this axis with negative

coordinates. Also Hungary (RC = 0.48), Bulgaria (RC = 0.28) and Mexico



(RC = 0.24) which were treated as supplementary variables, are also represented on

this axis with negative coordinates. All these countries are correlated to Condensed

Matter and anti-correlated to Particle Physics.

Factor ~P3: The third factorial axis accounts for 15.4% of the total variance in the multidimensional data. Chemical Physics and Nuclear Physics indicate greater

variance on this axis than on any of the first two axes. Figure 5 gives a unidimensional

representation of the main features of relationships between countries and subfields on this axis.

On the cloud of subfields, this factor is constituted by Condensed Matter

(AC = 22.2%), Chemical Physics (AC = 26.3%), Nuclear Physics (AC = 33.9%) and

Particle Physics (AC = 9 .3%) . Condensed Matter and Particle Physics are projected

on this axis with positive coordinates. These subfields are opposed to Nuclear Physics and Chemical Physics.

06-

- - DDR

Q3 SUN

AUT

PART

CHEM DEU . N - - ~ , S W E

-CAN \ Y U G

- 0 .~ - D N K

NOR

- - A R G

-0.6

Fig. 5. Positioning of significant countries and subfields on factorial axis qb 3 (coauthored publications)

118 Scientometrics 3l (1994)

P. s. NAGPAUL, L. SHARMA: RESEARCH OUTPUT AND COOPERATION IN PHYSICS

On the country cloud, this axis is constituted by FRG (AC = 16.8%; RC = 0.43),

Canada (AC = 12.4%; RC = 0.50), USSR (AC = 15.6%; RC = 0.40), Sweden

(AC = 5.1%; RC = 0.40), Denmark (AC = 10.0%; RC = 0.49), GDR (AC = 12.2%;

RC = 0.27), Austria (AC = 1.7%; RC = 0.41). Yugoslavia (RC = 0.33), Argentina

(RC = 0.60) and Norway (RC = 0.29) which are treated as supplementary variables

in the analysis are also represented on this axis. USSR, GDR and Austria are

projected on this axis with positive coordinates. These two countries are correlated to

Condensed Matter and Particle Physics. FRG, Canada, Sweden, Denmark,

Yugoslavia, Argentina and Norway are projected on this axis with negative

coordinates. These countries are correlated to Chemical Physics and Nuclear Physics

and anti-correlated to Condensed Matter and Particle Physics.

Comparison of configurations

The configurations for research output and ICOP's were matched using the computer program FMATCH, 19 based on Cliff's algorithm. 20 The matching is done

through orthogonal rotation of the two matrices to a compromising position, using a

least squares optimality criterion. This is analogous to finding the orientation of r

space and that of s space and matching the n projections in each of these spaces. The

axes of the two spaces are rotated so that the columns of the rotated matrices are as

similar as possible. The program yields two-dimensional plots and computes the goodness of fit index, which is equal to + 1 for perfect fit and equal to - 1 for worst

fit. The coordinates of the first three factorial axes were submitted to the program

for matching of the configurations. 21 The program indicated goodness of fit equal to

0.346, which implies that the fit is quite unsatisfactory.

An inspection of the two configurations indicates that the configurations differ in

the composition of the factorial axes, both on the subfield and country clouds. This

implies that the patterns of research output and international coauthorship of these

countries do not match with each other. The differences in the specificities and

correlations of the top ten countries (USA, USSR, FRG, Japan, UK, France,

Canada, India, Italy and Switzerland) are briefly discussed below.

Factor dol: On the cloud of subfields, the composition of the first factorial axis is

more or less the same in both the configurations. Condensed Matter is opposed to

Acoustics, Fluids & Plasmas, Optics and Mechanics in these two configurations. In

the configuration for research output, Chemical Physics is opposed to Condensed

Sr162 31 (1994) 119


Matter, whereas in the configuration for transnational cooperation, instead of Chemical Physics, Applied Physics is opposed to Condensed Matter. Particle Physics and Nuclear Physics are also projected on the first factorial axis in the configuration for transnational cooperation.

On the country cloud, USA, UK, and Canada are associated and correlated to Fluids & Plasmas, Acoustics, Optics and Mechanics in both the configurations.

USSR is correlated to Condensed Matter in both the configurations. In contrast, India is correlated to Condensed Matter in the configuration for research output, but anticorrelated to this subfield in the configuration for transnational cooperation.

The composition of the second and third factorial axes, both on the clouds of subfields and countries, are quite different.

Discussion

The foregoing analyses of research output and transnational cooperation in Physics subfields indicate that there is no one-to-one correspondence between these two entities. This is true for research fields as well as for countries. For instance, Applied Physics - a relatively large subfield - accounting for about 23.1% of total publications in Physics, accounts for only 9.7% of ICOP's. In the case of countries, this can also be visualized by comparing the values of activity index and collaboration index. These results imply that it is not only the internal dynamics of science, but there are also other factors, socio-economic and geopolitical in nature, that can influence the degree of transnational cooperation.

The methodology adopted in this study (viz. correspondence analysis) for identifying clusters of countries with similar profiles of research output (or transnational cooperation) is superior to hierarchical cluster analysis, which

precludes the possibility of a country to belong to more than one cluster. In contrast, correspondence analysis allows for the establishment of overlapping clusters. Further, the overlapping structure in the data can be spatially represented to reveal the correlations and specificities of different clusters of countries to various subfields.

The distances between the countries in the configuration for research output and transnational cooperation indicate ~that profiles of research and transnational

cooperation of even the big league - top ten countries - are not identical, implying differences in their national science policies. Even countries which are geographically close to each other do not have identical patterns of transnational cooperation. These



results imply that the countries have not only different levels of access to the international network of science, but also have different patterns of access.

Matching of the configurations for research output and transnational cooperation reveals that the matching is quite unsatisfactory, implying lack of concordance between national policies for research and transnational cooperation in Physics. However, this does not mean that concordance between the two policies is desirable and worth pursuing. That would essentially depend upon the particular circumstances of the countries and opportunities available to them for transnational collaboration.

Acknowledgement is due to the Council of Scientific & Industrial Research (India) for financial support under the ESS 'Programme of Research in Applied Scientometrics'.

Notes and references

1. T. BRAUN, E. GOMEZ, A. MENDEZ, A. SCHUBERT, International coauthorship patterns in Physics and its subfields: 1981-1983, Scientometrics, 24 (1992) 181 -200.

2. T. LUUKKONEN, O. PERgSON, G. SIVERTSEN, Understanding patterns of international scientific collaboration, Science, Technology and Human Values, 17 (1992) 101 - 126.

3. Measuring Internationalization of Science, Laboratoire d'Evaluation ct de Prospective Internationales (CNRS), Paris, 1993, p. 63.

4. F. NAmN, K. STEVENS, E, S. Wrrtqt.ow, Scientific cooperation in Europe and the citation of multinationally authored papers, Scientometrics, 21 (1991) 313-323.

5. For example, Science Indicator Series of USA, France, Japan, etc. incorporate data and analyses on internationally coauthored publications.

6. See for example, op. cit. Refs. 2, 3; IL J. W. TIJSSEN, Literature based statistical analysis of international scientific cooperation: An exploratory case study of the Netherlands, In: R. J. W. TIJSSEN, Cartography of Science: Scientometric Mapping with Multidimensional Scaling Methods, DSWO Press, Leiden University Leiden, 1992, pp. 145 - 159.

7. T. BRAUN, E. GOMEZ, A. MEHDEZ, A. SCHUBERT, op. cit. Ref. 1. 8. G. SALTON, D. BEERGMAR, A citation study of computer science literature, IEEE Transaction in

Professional Communication, PC-22, 3 (1979) 393- 440. 9. L. LEnART, A. MOPdNEAU, K. M. WARWICK, Multivariate Descriptive Statistical Analysis, John Wiley

& Sons, New York, 1984. 10. This methodology has been used by several researchers, for example, IL J. W. TUSSEN, op. cit. Ref.

5; see also papers in Ref. 3. 11. F. NARIN, et al., op. cir., Ref. 4. 12. See for example, T. LUUgKOHEN, O. PERSSOS, G. SrVEgSEH, op. cit., 1; P. CABO, T. H. A. BIJMOLT,

International R & D networks: the Eureka map, paper presented at the Fourth International Conference on Bibliometrics, lnforrnetrics and Scientometrics, Berlin, 11-16 September, 1993.

13. J.D. FRAME, Mainstream research in Latin America and Caribbean, Interciencia, 2 (1977) 143-148. 14. A. SCHUBERT, T. BRAUN, Relative indicators and relational charts for comparative assessment of

publication output and citation impact, Scientometrics, 9 (1986) 281- 291.

Scientometric$ 31 (1994) 121


15. M.P. CARPENTER, F. Gmn, M. HARMS, J. IRVINE, B. R. MARTIN, F. NARIN, Bibliometrics profile for British academic institutions; An experiment to develop research output indicators, Scientometrics, 14 (1988) 213-233.

16. P. S. NAGPAUL, N. PANT, Crossnational assessment of specialization patterns in Chemistry, Scientometrics, 27 (1993) 215 - 235.

17. L. Lm~ART, A. MOmNF.AU, K. M. WARWICK, op. cir., Ref. 9. 193-222. 18. Countries with less than 1000 publications were treated as supplementary variables in the analysis to

reduce noise in the data. 19. F~t~TCn is a module of the computer program 'Multidimensional Statistical Package' (PC-MDS)

developed by S. M. SMrra, Institute of Business Management, Brigham Young University, Provo, Utah, USA.

20. N. CUFF, Orthogonal rotation to congruencr Psychomew/ka, 31 (1968) 33-42. 21. The coordinates of thirteen countries, which were treated as supplementary variables in the

correspondence analysis were excluded in the matching of the two configurations. This was necessary since the two configurations were determined only by the active variables.


research output and transnational cooperation in physics subfields: a multidimensional analysis

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