Friday, August 24, 2018

Why is Australia doing well in the Shanghai rankings?

I am feeling a bit embarrassed. In a recent post I wrote about the Shanghai Rankings (ARWU) being a bit boring (which is good) because university ranks usually do not change very much. But then I noticed that a couple of Australian universities did very well in the latest rankings. One of them, the Australian National University (ANU), has risen a spectacular (for ARWU) 31 places over last year. The Financial Review says that "[u]niversity scientific research has boosted the position of two Australian universities in a global ranking of higher education providers." 

The ranking is ARWU and the rise in the ranking is linked to the economic contribution of Australian universities, especially those in the Group of Eight.

So how well did Australian universities do? The top performer, as in previous years, is the University of Melbourne, which went up a spot to 38th place. Two other universities went up a lot in a very un-Shanghainese way, ANU, already mentioned, from 69th to 38th place and the University of Sydney from  to 83rd to  68th

The University of Queensland was unchanged in 55th place while Monash fell from 78th to 91st  and the University of Western Australia from 91st to 93rd. 

How did ANU and Sydney do it? The ANU scores for Nobel and Fields awards were unchanged. Publications were up a bit  and papers in Nature and Science down a bit.  

What made the difference was the score for highly cited researchers, derived from lists kept by Clarivate Analytics, which rose from 15.4 to 23.5, a difference of 8.1 or, after weighting, 1.62 points of the overall score. The difference in total scores between 2017 and 2018 was 1.9 so those highly cited researchers made up most of the difference.

In 2016 ANU had two researchers in the list, which was used for the 2017 rankings. One was also on the 2017 list, used in 2018. In 2017 there were six ANU  highly cited researchers, one from the previous year and one who had moved from MIT. The other four were long serving ANU researchers.

Let's be clear. ANU has not been handing out unusual contracts or poaching from other institutions. It has grown its own researchers and should be congratulated.

But using an indicator where a single researcher can lift a top 100 university seven or eight places is an invitation to perverse consequences. ARWU should consider whether it is time to explore other measures of research impact.

The improved scores for the University of Sydney resulted from an increase between 2016 and 2017 in the number of articles published in the Science Citation Index Expanded and the Social Science Citation Index.

Saturday, August 18, 2018

Who Cares About University rankings?

A paper by Ludo Waltman and Nees Jan van Eck asks what users of the Leiden Ranking are interested in. There's some interesting stuff but for now I just want to look at where the users come from.

The top ten countries where visitors originate are:

1.  USA
2.  Australia
3.  Netherlands
4.  UK
5.  Turkey
6.  Iran
7.  South Korea
8.  France
9.  Germany
10. Denmark.

The authors consider the number of visitors from Australia, Turkey, Iran and South Korea to be "quite remarkable."

Let's look at other signs of interest in rankings. Here are the top countries for respondents to the 2018 QS academic survey:

1.  USA
2.  UK
3.  Malaysia
4= Australia
4= South Korea
4= Russia
7= Italy
7= Japan
9= Brazil
9= Canada

And here are the top ten countries for visitors to this blog:

1. USA
2. UK
3. Russia
4. France
5. Germany
6. Ukraine
7. Canada
8. Malaysia
9. Australia
10. Singapore.

The three countries on all three lists are UK, USA and Australia. The countries on two lists are South Korea, Russia, Malaysia, France, Germany and Canada.

Saturday, August 11, 2018

Will THE do something about the citations indicator?

International university rankings can be a bit boring sometimes. It is difficult to get excited about the Shanghai rankings, especially at the upper end: Chicago down two places, Peking up one. There was a bit of excitement in 2014 when there was a switch to a new list of highly cited researchers and some universities went up and down a few places, or even a few dozen, but that seems over with now.

The Times Higher Education (THE) world rankings are always fun to read, especially the citations indicator, which since 2010 has proclaimed a succession of unlikely places as having an outsize influence on the world of research: Alexandria University, Hong Kong Baptist University, Bilkent University, Royal Holloway University of London, National Research University MEPhi Moscow, Tokyo Metropolitan University, Federico Santa Maria Technical University Chile, St George's University of London, Anglia Ruskin University Cambridge, Babol Noshirvani University University of Technology Iran.

I wonder if the good and the great of the academic world ever feel uncomfortable about going to those prestigious THE summits while places like the above are deemed to be the equal for research impact or the superior of Chicago or Melbourne or Tsinghua. Do they even look at the indicator scores?

These remarkable results are not because of deliberate cheating but of THE's methodology. First, research documents are divided into 300 plus fields, five types of documents, and five years of publication, and then the world average number of citations (mean) is calculated for each type of publication in each field and in each year. Altogether there are 8000 "cells" with which the average of each university in the THE rankings is compared .

This means that if a university manages to get a few publications in a field where citations are typically low it could easily get a very high citations score. 

Added to this is a "regional modification" where the final citation impact score is divided by the square root of the score of the country in which the country is located. This results in most universities receiving an increased score which is very small for those in productive countries and very high for those in countries that generate few citations. The modification is now applied to half of the citations indicator score.

Then we have the problems of those famous kilo-author mega-cited papers. These are papers with dozens, scores, or hundreds of participating institutions and similar numbers of authors and citations. Until 2015 THE treated every author as as though they were the sole author of a paper, including those with thousands of authors. Then in 2015 they stopped counting papers with over a thousand authors and in 2016 they introduced a modified fractional counting of citations for papers with over thousand authors. Citations were distributed proportionally among the authors with a minimum allotment of five per cent.

There are problems with all of these procedures. Treating every  authors as as the sole author meant that a few places can get massive citation counts from taking part in one or two projects such as the CERN project or the global burden of disease study . On the other hand excluding mega papers is also not helpful since it omits some of the most significant current research.

The simplest solution would be fractional counting all around, just dividing the number of citations of all papers by the numbers of contributors or contributing institutions. This is the default option of Leiden Ranking and there seems no compelling reason why THE could not so.

There are some other issues that should be dealt with. One is the question of self-citation. This is probably not a widespread issue but it has caused problems on a couple of occasions.

Something else that THE might want to think about is the effect of the rise of in the number of authors with multiple affiliations. So far only one university has recruited large numbers of adjunct staff whose main function seems to be  listing the university as a secondary affiliation at the top of published papers but there could be more in the future. 

Of course, none of this would matter very much if the citations indicator were given a reasonable weighting of, say, five or ten percent but it has more weight than any other indicator -- the next is the research reputation survey with 18 %. A single mega-paper or even a few strategically placed citations in a low cited field can have a huge impact on a university's overallscore.

There are signs that THE is getting embarrassed at the bizarre effects of this indicator. Last year Phil Baty, THE's ranking editor,  spoke about its quirky results. 

Recently, Duncan Ross, data director at THE, has written about the possibility of of a methodological change. He notes that currently the  benchmark world score for the 8000 plus cells  is determined by the mean. He speculates about using the median instead. The problem with this is that a majority of papers are never cited so the median for many of the cells is going to be zero. So he proposes, based on an analysis from the recent THE Latin American rankings, that the 75th percentile be used. 

Ross suggests that this would make the THE rankings more stable, especially the Latin American rankings where the threshold number of articles is quite low. 

It would also allow the inclusion of more universities that currently fall below the threshold. This, I suspect, is something that is likely to appeal to the THE management.

It is very good that THE appears willing to think about reforming the citations indicator. But a bit of tweaking will not be enough.