All 5 entries tagged Web Of Knowledge
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July 22, 2011
Writing about web page http://science.thomsonreuters.com/techsupport/datachange/
If you're an author and you've been checking which of your articles are indexed on Web of Science/Web of Knowledge, maybe looking at how many citations you've got and maybe putting together a ResearcherID profile, and you come across some mistake on Web of Science then you can make a data change request at this web page.
The easiest way to do this is when you're viewing the erroneous record in Web of Knowledge: look out for the link on the right hand side "Suggest a correction" which will take you to this form, pre-filled with the metadata from the record.
May 16, 2011
Writing about web page http://ideas.repec.org/top/index.html
RePEc is a database for Economics papers and outputs, and citation analysis has been carried out, along with other measures, to provide rankings for items, series, authors, institutions and regions. This page lists these rankings and has links to information about how they were calculated.
It's a really great resource if you're looking to benchmark or compare one entity against another. RePEc's IDEAS offers a selection of different measures and rankings for each type of entity. Item rankings offered include one by simple citation count and others which are citation counts weighted by various factors, eg the impact factor of the citing publication (termed "recursive" by RePEc) or a discount for the age of the citation. A ranking by item downloads within RePEc is also included, and even by abstract viewings.
Series rankings include journals by impact factor, which is calculated based on RePEc's own data and is offered in varieties like those for items, including a weighted or recursive score based on the impact measures of the citing sources. I like the simple feature that it includes journals by their full title, which Web of Science's JCR impact factor listings do not: I am not so familiar with journal titles or their abbreviations that I find the JCR list easy to interpret!
Authors are only ranked if they are registered with RePEc and the top 10% appear on their summary table. Even if you're not in the top 10% it seems worthwhile registering because you can access data about your own publications. This must be so much more meaningful than looking up your own h-index on Web of Knowledge, in isolation. Even though you can look at the profiles of highly cited authors on Web of Knowledge, these won't all be people from within your own field and comparing rankings based on citation scores across different disciplines is not all that meaningful because citation practices vary across the disciplines.
RePEc seems to make it easy for authors to use bibliometrics and other measures in an intelligent and balanced manner and in that sense Economists seem to be very well provided for. I'm not a registered author so I can't see what goes into the updates or reports that authors can see, and I know that citations are scraped and parsed by software so I wonder how accurate the data is in the first place, but presumably as a registered author you can correct any errors.
All this is great for Economists and probably those in related disciplines, but I wonder what effect such specialisation of both data source and methodology is going to have on the use and impact of bibliometric measures? I'm sure others will have compared Web of Knowledge rankings with those of RePEc, so I'll have to investigate further!
November 04, 2010
The slides from the session I attended last week are now available online at: http://wok.mimas.ac.uk/support/documentation/#presentations
November 02, 2010
I attended a training course held at Oxford University last Friday: it was a session delivered through Mimas, and provided by Thomson Reuters (TR) who publish citation data.
The session began with reference to two University rankings, which I have blogged about in the past. The ARWU from ShanghaiRanking and the Times Higher Education (THE) World University Ranking, both of whom use Thomson Reuters' citation data. There are other University Rankings, of course: QS used to provide THE's ranking and now have their own World University Ranking, and there is the Webometrics Ranking Web of World Universities, who do look at citation data but they use TR's competitor Elsevier's data, available in their product Scopus. And there are other rankings too, which are not at all interested in citations... but the two mentioned on Friday were ARWU and THE.
ARWU's approach is interesting: they are interested in whether any researchers have published in two particular high profile and cross-disciplinary journal titles: "Nature" and "Science". Our trainer also mentioned that ARWU seem to use other citation data, possibly from TR's Essential Science Indicators product. THE's ranking methodology shows that about a third of their ranking score is due to citations data from TR. More reading on University rankings: "International ranking systems for universities and institutions: a critical appraisal" http://dx.doi.org/10.1186/1741-7015-5-30 looks particularly interesting and it cites some other important looking articles on the topic, although all are too old to shed light on the THE's latest methodology, and the way in which THE have normalised for discipline seems to me to be particularly significant.
Our trainer did suggest that we can create our own normalisation by searching for articles in a given journal or from a given subject set, and in a particular year and then creating a report on Web of Science, which would tell us the expected citation rate for that set of articles. (This is the small link towards the top right hand side of the screen "Create citation report", which you can do for any set of results in Web of Science.) I think it's unlikely that the THE did this: they would probably have bought the raw data to manipulate, or at least have purchased it through InCites where you can get reports on expected citation rates.
Criticising the measurements
When using these kinds of citations metrics, or indeed any bibliometrics, you need to bear in mind the source of your data, and our presenter did show us some slides indicating that 40% of the journals in Web of Science carry the vast majority of all citations. TR do add new journal titles to their collection (and they drop some), and they evaluate about 2,500 new titles each year for suitability. They have records for all citations from the journals they index, i.e. including those to journals which they do not index. This means that they have data to indicate that the journals they have not indexed are in fact attracting lots of citations and therefore they ought to cover them...
But we're still only talking about journals and conference proceedings, in the main. TR have mentioned a couple of times recently that they are planning some kind of citations index for books to be launched next year, but they are playing their cards very close to their chests about their source of data for any such index!
We spoke about self-citations and whether these ought to be included in citation measuring sets. I would recommend self-citing from a "bibliometrics optimisation" perspective, although of course there are other reasons than citation measurements to self cite or not.
A colleague from Warwick who was also at the session, Professor Robert Lindley who heads our Institution for Employment Research, also suggested that TR stopped referring to the measure of how many articles an author (or unit) has published as a measure of "Productivity". It is a volume of output, perhaps, but even then only of particular outputs so it would be best to label it as just what it is, the number of journal items published. TR also suggest an "Efficiency" rating which is the percentage of papers with citations as opposed to those without any, and an "Impact" rating of the average number of citations per paper (as used for Journal Impact Factors). Pitfall to avoid: this citation impact is not at all the same as impact in the context of the REF: REF impact is about effects outside the scholarly community, whilst TR's measurement of citations is an activity that clearly happens within the scholarly community.
Journal Impact Factors
The calculation of the Journal Impact Factor was explained, and the purpose of the 5 year Journal Impact Factor as well, which was useful for me to pick up on: I wondered why there were two measures! The original one was measured over two years, and a graph showing the average time for citations for an article to appear by discipline clearly showed that for some disciplines, the peak number of citations will happen after two years since publication. In other words, the measure of a journal's impact being over a two year period was advantaging journals from disciplines which are quickest to cite. These are primarily science, technology and medicine journals, so the 5 year Journal Impact Factor could be really useful for those involved cross-disciplinary and interdisciplinary research who are looking to target journals for their articles which will get them the best reach within the scholarly community as a whole. The 5 year JIF is a better measure if you are trying to compare journals from different disciplines... although of course, it can never take into account the relative value of a citation from each discipline, and indeed the fact that citations from some disciplines will happen in books or other kinds of publication which WoS doesn't (currently) index...
There was more about the H-index and some useful slides that I hope to get a link to in the near future.
May 04, 2010
Last Friday afternoon I attended a training session run by Rachel Mangan, who is employed by Thomson Reuters to deliver training on Web of Knowledge stuff. It was an event co-ordinated by MIMAS who are funded by the JISC and held at Oxford University Computing Services.
Rachel's main perspective was to plug the additional features that will be coming in version 5 of Web of Knowledge. (The current live version is version 4, but anyone can check out version 5 by clicking on the top right hand side link on the WoK page... I just wouldn't recommend it because it seems like their data behind version 5 is decidedly dodgy!) The new features look as though they will be useful for the sophisticated searcher.
I learnt a new word, which is "lemmatisation". It is something that they do to your search terms through applying some kind of dictionary (not one we can look at), so that if you type in "mice" as a keyword they will also look for results with the word "mouse" in them. And they will associate the participles of irregular verbs for you, which is something that truncation and wild-card searching can't always do... eg if you type in "run" you will also get "ran" and "running" and so on. I'm not sure how useful this lemmatisation will actually be, purely because I'm not sure how many people will know what it means or what it is doing for them! I think it would be more useful if they just run these searches and then when returning the results, they explain that they also included variations, and list the variations they used whilst giving you the option to turn individual ones off... and avoid the word "lemmatisation" altogether!
I find it disappointing that there is no way to link the bibliometric reporting functions of Web of Science with ResearcherID libraries. It would be so useful for authors to be able to create a collection of their own articles on ResearcherID and have all those articles assigned to them on Web of Science... but then there is nothing to stop them from claiming lots of articles for their own which are not theirs at all, on ResearcherID. Indeed, for those who upload their library of references to ResearcherID from their EndNote files, they are positively encouraged to include others' work because they are allowed 3 folders of references on ResearcherID. Given that one of these folders is always going to be called "My Publications" (default and the only option you get if you're not uploading from EndNote) then an author would probably be foolish to put his or her own publications anywhere other than the MyPublications list and want to use the other folders for "papers I'm reading" or "articles which cite me" or whatever they want to call them.
I still have more work to do with regard to investigating the usefulness (or otherwise) of ResearcherID, amongst other author profile systems on the web. How many Warwick authors are using it already... and do they like it? Some improvements are in the pipeline but I am yet to be convinced. If researchers here asked for it then I'd gladly run a session here on how to get your ResearcherID profile up and running... but I might be better off starting with stuff on which places on the web an author is best placed to get a profile up. Which profile sites will gain them most attention amongst their peers? Which are easiest to get a profile up onto? Which sites offer them additional functions that will be useful in saving them time elsewhere in their career?
Rachel also demonstrated a handy feature of EndNote Web where you can store YouTube clips and it will automatically populate various metadata fields of your bib record for the video on your EndNote library. If you've installed Cite-While-You-Write onto your PC, from EndNote Web. It seems to work very much like Zotero does with Mozilla Firefox. Again, I'm not altogether sure which are the best reference management softwares out there, but it's something that I'm learning, very fast! I guess that the best one for Warwick researchers to use is EndNote Web because it's more powerful than many others so you can do more with it... and of course we have experts in the library who can help you with it.
There's a new collection called Biosis coming on Version 5 of WoK. It overlaps with content already indexed by WoS but I guess it's handy for those in the life sciences to have a specialist database to search. It allows more powerful searching if you are accessing a specialist collection with specialist metadata, for one thing. And of course, not all of the content is overlapped, so it does expand WoK coverage. It's something that there is often confusion about, this difference between WoK and WoS, with the latter being only one of the databases included in the WoK.
Apart from the "lemmatisation", in version 5 they are also introducing a way to stop them from ignoring your "stop words"... by which I mean that it will be possible to search for "further education" without them ignoring the word "further" because it appears on their list of stop words. Likewise for "vitamin A", which has not been possible because "a" is another stop word. And they're introducing left hand truncation, eg *phosphate to get monophosphate and 3-phosphate and other variations. Searchers might also find it useful to click on a link within a results set to read the abstract for an invidual record, which is also due in version 5.
Version 5 will also see a removal of the 100,000 item limit to a search set. Handy if you want to know everything ever published in a particular country since 1900, ie if you are HEFCE... except of course that WoK doesn't index everything! It's in the region of 3 million articles, by the way. Or it might not be because the earliest record only dated back to 1945 and it ought to go back earlier. Like I said earlier, the data behind version 5 in it's current trial iteration doesn't seem that reliable at the moment.
Finally to the bit which I was most interested in: the bibliometrics part. Lots of people who have attended these sessions have asked for one dedicated to bibliometrics, so keep an eye out for TR/MIMAS events in the future on bibliometrics. WoK 5 will have additional cited reference search fields, searching in all citation sources. Your citation sources for WoK 5 are WoS, the Biosis citation index and the Chinese Science Index. You will get access to the Biosis one if you play around with version 5 now, in its trial version. You won't get the CSI unless your institution subscribtes to it. WoS comes to us in versions 4 and 5 through a JISC deal. There are other databases on WoK, but the others are not citation sources.
Each of the citation source databases on WoK has its own citation count, and if you're doing a citation search then you can refine it by database. Each of the databases will generate a citation report for you. This powerful feature is almost hidden in WoS behind a tiny icon which says "citation analysis report" or something to that effect. Version 5 will allow you to run a citation report from a marked list, which is how you can compare citation scores from the different database sources, by adding them to your marked list.
Rachel's slides go on to list more general stuff about why and how research performance might be evaluated, who does the evaluation, and what types of data are used in bibliometrics. I am still digesting these, along with all that I learnt at the other bibliometrics event last week, and shall blog collated thoughts in a separate posting!