Figure 1.
Citation impact of six countries (China, UK, Germany, France, Japan, and USA) calculated relatively to four subject areas (natural sciences; engineering and technology; medical and health sciences; and agricultural sciences).
For each country, the Spearman’s rank-order coefficient for the correlation between publication year and citation impact is given; an asterisk signifies a statistically significant coefficient (the “true” coefficient, the population coefficient, is likely to be above 0). A high correlation coefficient indicates an increasing or decreasing trend in citation impact values. Source: InCitesTM Thomson Reuters [9].
Table 1.
Minimum, maximum, mean, and standard deviation of citation impact values by subject area and country (N is the number of publication years included in the analysis).