The 2008 performance measures are composed of eight indicators. One indicator used in the 2007 ranking (“number of subject fields where the university shows excellence”) has been removed and the weightings of the 2008 indicators have been adjusted accordingly. The indicators together represent three different criteria of scientific papers performance: research productivity, research impact, and research excellence. Table 1 lists the indicators and shows their respective weightings for the indicators.

Table 1: The Criteria, Indicators, and Their Respective Weightings Used for the Overall Performance Based Ranking

Research Productivity:

The number of articles published in peer-reviewed academic journals is an appropriate indicator of the productivity of a research institution. To fairly represent a university’s on-going and current research productivity, this project employs two indicators: the number of articles in the last eleven years (1997-2007), and the number of articles in the current year (2007).

“Number of articles in the last 11 years” draws data from ESI, which include 1997-2007 statistics of articles published in journals indexed by SCI and SSCI. “Number of articles in the current year” relies on the 2007 data obtained from SCI and SSCI, which were searched between Jan 19 and Jan 31, 2008.

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 a fair representation of a university’s research impact regardless of its size and faculty number.  Thus, this project measures research impact 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 1997-2007 citation statistics from ESI. “Number of citations in the last 2 years” draws 2006-2007 citation statistics 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 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 via the use of the 2006-2007 data from SCI and SSCI. It is defined as “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 1997 to 2007. ESI defines Highly Cited Papers as SCI /SSCI-indexed papers that are cited most (in the top 1% of the total papers indexed in the same year) within the last 11 years.

“Number of articles of the current years in high-impact journals” employs data from JCR, which supplied the impact factor of each journal in its subject field. The impact factor of a journal is the number of citations to the papers published in that particular journal within the previous two years divided by the number of that journal’s papers within the previous two years. A journal with a higher impact factor means its articles are more frequently cited by other journals, thus suggesting its higher scholarly value. This project defines high-impact journals as journals whose impact factors are ranked as the top 5% of the total journals within a specific subject category. 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 subject.