Like the overall performance ranking, the field-based ranking utilized bibliometric data of 1998-2008 from ESI, WOS, and JCR. It employed ISI’s subject categorization of the journals and ranks the world universities accordingly.

Similar to the overall performance ranking, this field based ranking project first analyzed the top 400 universities from ESI database by number of articles and number of citations in the last eleven years to compile a list of education institutions that provided bachelor’s and graduate degrees for each field. Through the comparisons of our primary list and the universities included in THES and ARWU, the top four hundred universities in the six fields were selected as the final list for our analysis. The final compilation for ranking included 504 universities in Agriculture and Environment Sciences, 492 universities in Engineering, Computing and Technology, 487 universities in Clinical Medicine, 462 universities in Life Sciences, 505 in Natural Sciences, and 468 in Social Sciences.  

The concept of authority control  was employed to retrieve data indexed under different forms of a university’s name in the aforementioned databases – i.e., the official name, the abbreviated and other possible forms of the names. This project also considered the mergers and splitting of universities (or different campuses in a university system) and included publications by a university’s affiliated institutions such as research centers and university hospitals. This effort ensured the accuracy of each university’s number of published journal articles and the subsequent statistics of their citations.

The indicators employed in the field-based ranking and their respective weightings in the composite measures are identical to those used in the overall performance ranking. Table 2 shows the criteria, indicators, and their respective weightings used by field-based ranking.

Table 2: The Criteria, Indicators, and Their Respective Weightings Used by Field-based Ranking

Research Productivity:

The number of articles published in peer-reviewed academic journals is frequently used to indicate the productivity of a research institution. To objectively represent a university’s on-going and current research productivity, this project employs two indicators: the number of articles in the last eleven years (1998-2008) and the number of articles in the current year (2008) for each of the six fields.

“Number of articles in the last 11 years” draws data from ESI, which include 1998-2008 statistics of articles published in journals indexed by SCI and SSCI in each field. “Number of articles in the current year” relies on the 2008 data in each field obtained from SCI and SSCI, which were searched between January 1 and January 31, 2009.

Research Impact:

The number of citations on a particular academic article within a specific time frame is a commonly accepted indicator for that article’s impact. This project considers both the long-term and short-term impacts of a particular research and seeks to provide fairer representation of a university’s research impact regardless of its size and faculty number. Thus, this project measures research impact for each of the six fields by: the number of citations in the last eleven years, the number of citations in the last two years, and the average number of citations in the last eleven years.

‘Number of citations in the last 11 years” draws 1998-2008 citation statistics in each field from ESI. “Number of citations in the last 2 years” draws 2007-2008 citation statistics in each field from SCI and SSCI at WOS, which include citation statistics updated to the dates of retrieval. “Average number of citations in the last 11 years” is the number of articles in the last eleven years divided by the number of citations in the last eleven years.

Research Excellence:

This project assesses each university’s research excellence in each of the six fields by the following indicators: the h-index of the last two years, the number of Highly Cited Papers from ESI and the number of articles in high-impact journals in the current year (hi-impact journal articles). “H-index of the last 2 years” measures both the quantity and quality of a university’s research in each field via the use of the 2007-2008 data from SCI and SSCI. A university has index h if h of its Np papers in the last two years have at least h citations each and the other (Np – h) papers have ≦h citations each.

“Number of Highly Cited Papers” utilizes data from ESI, which include statistics of “Highly Cited Papers” from 1998 to 2008. ESI defines Highly Cited Papers as SCI /SSCI-indexed papers that are cited most (in the top 1% of the total papers for each of the six fields indexed in the same year) within the last ten years.

“Number of articles in high-impact journals in the current year” employs data from JCR, which supplies the impact factor of each journal in its subject field. This project defines high-impact journals as journals whose impact factors ranked as the top 5% of the total journals within a specific field. With high-impact journals lists derived from JCR, this project is able to count the numbers of each university’s articles published in high-impact journals by each field.

The procedures for data processing are as follow. First, the project staff conducted authority control on the various forms of a university’s name and inspected all the SCI/SSCI bibliographic records in which the address field contained one of the forms of the university’s name. An accurate number of the total articles in each of the six fields from a university was obtained after removing duplicate records containing different forms of that university’s name. Second, using SCI/SSCI, this project obtained the total number of citations in each field by adding the number of citations to each article belonging to that field and from the university, starting from the article’s inclusion in SCI/SSCI to the date of our retrieval.

Some university systems have several campuses. A few campuses within a particular university system may have been commonly perceived as individual institutions. However, they are indexed in ESI only by the university system name. For example, University of Wisconsin-Madison and University of Wisconsin-Milwaukee are not differentiated in ESI (they are both indexed under “Univ Wisconsin”) although they are often perceived as two individual universities. This project corrected the flaw by manually searching SCI/SSCI in order to identify the actual number of articles and citations of these articles produced by each individual campus in each of the six fields. Likewise, this project employed the same manual searching procedures to ensure that the measurement of each university’s Highly Cited Papers had fairly represented the research performance of each individual university campus by field.

Based on the measurement procedures, this project calculated a university’s field-based scores by the eight indicators. For each indicator, the university with the highest number received the maximum points (100); the other universities’ numbers were subdivided by the highest number and were converted decimally into their respective scores. For example, if University A had the highest number M for Indicator X, it received 100 for that indicator, while University B with a number of N received (N/M×100) for that particular indicator. Finally, the project calculated the final score of each university by the indicator weightings presented in Table 2 and sorted the universities by their final scores for each of the six fields. Universities with the same scores were sorted alphabetically. It should be noted that many universities obtained similar scores, and the slight differences of the final scores must be interpreted carefully. A university’s slightly higher score than another university’s may not necessarily suggest its superiority in scientific research because the two universities might be in very close proximity in the ranking.

The HEEACT ranking categorizes all subject disciplines into six fields and ranks each university’s performance by fields. Table 3 shows the six fields of the HEEACT field-based ranking. The detailed subject categories of each field are listed in the Appendix.

Table 3: Six Fields of the HEEACT Field-based Ranking

Appendix Subject Categories by Field