Getting Started

how can we calculate normalized citation and average normalized citation and what is the significance of this?

I have 1,271 articles and when I go to choose the type of analysis only co-authorship and co-occurrence options are possible.
AND
When I choose co-occurrence an error message pops out "Insufficient number of keywords. There must be at least three keywords".
Help please and thx

My computer environment is: masOS Mojave. My vosviewer has been running without any problems before. Recently, clicking and finishing will cause a flashback. This is the case every time. This crash phenomenon can also be caused by a small amount of data, and java environment everything is normal. What should I do? Please help.

Is there a way to open the map file .txt In Excel which would allow editing of the individual outputs. I know when I opened it in Excel it currently puts all the information into a single column is there anyway to separate it out into individual columns?

I am missing the .jar file after I download it from vosviewer.com/download for Windows. I need the .jar file to take a network from Rstudio into vosviewer. How can I get the file? Am I doing something wrong?

Hi!
Is there a way that I can exclude certain keywords from the co-occurance map (if they're remote and very scantily connected) using the thesaurus file?
Thanks!

I am a bit confused. With a total of 78 papers, I am conducting Co-citation analysis at the author level. Link Strength between Author A and Author B is 310. Does it mean that Author A and B were co-cited 310 times in the references of included papers? If not, then what should be the interpretation of this link strength value between two authors.
Thanks in advance

Hi
I am using the temporal overlay on a keyword map and would like to affirm if my understanding is correct.
I think that for each keyword VOSviewer identifies the distribution of publication years for documents associated with the keyword. Then an algorithm is used to identify when the keyword has been most popular.
What is the algorithm? For example, do you use the mean, median or another formula to determine the time period and color associated with a keyword?
Thanks.
Philip

Hi, I love Vosviewer but I want to clean the data that I import first, and the easy tool that I have to do that is Excel ( I don't know how to program :( ), so I want to know if I can somehow import excel data to Vosviewer or If you recommend any free tool for cleaning data. Thanks :)

I would like to ask whether it is possible to check discipline-retained citation ratio. For example, if Paper A belongs to neuroscience (WoS category or Scopus subject area), how many times it is cited by neuroscience papers and non-neuroscience papers?
Method 1: From WoS / Scopus, I can generate a list of papers citing Paper A, and then check the category / subject area distribution of these citing papers. This should work for a single paper (e.g. Paper A) but do not work for a collection of papers (e.g. if I want to check a collection of Papers A to E). Because a neuroscience paper can contribute to multiple cites, such as cites to all Papers A to E. By this method, 5 citations will show as a single citing paper in the output.
Can VOSviewer or other solutions help? Would be great to have your recommendations on this. Thank you very much for your time.
Best regards, Andy

Just wondering if you can help me I am using vosviewer as part of a systematic review around domestic violence. When I separate the citations for a map based on text data into yearly sections 5 years the term partner violence is highly prevalent throughout the data set. With over 807 occurrences out of 2288 citations. However when I add all the citations together and carry out the same analysis the term does not even appear and the number of the individual terms be mentioned separately is not near the 807. Just wondering why this may be occurring as we were planning to do the separate five year analysis and the combined data set analysis? It is difficult to explain why a term can be so highly prevalent throughout the data set was then not appear when you combine them.
Kind regards James

Not directly related to VosViewer software, but is there a way to export bibliometric metadata of more than 500 references at once in WoS?

How can I get to know about the most productive author by using VOSviewer?

when i tried to open map, and has finished selecting VOSviewer map file and VOSviewer map file, but it showed error notification，and about 15 seconds later, VOSviewer quit suddenly.

Hi,
Thanks for a wonderful tool btw! It's absolutely fantastic.
I have followed all steps as laid out while exporting from Web of Science. However, when I select 'Create map based on network data' and pick the .txt file (exported from WoS), I get an error message 'incorrect use of quotes'. Any particular reason?
Can I receive any help?

Vos Viewer - End Note
Dear Ludo,
The answer you gave on April 19th is perfectly correct. However, there are conversations in this blog that explain in detail the procedure for exporting from EndNote. I use EndNote X7 and never find any problem.
Greetings

OK I'm sorry can u please briefly explain if I have an end note library how i can get the essential data and how to export it from end note what extension and how to import it to VOS viewer to get the authorship map since I'm having a serious difficulty figuring this out

Dear Ludo,
I am very enthusiastic about your software tools. And I hope that you do not mind my asking three related questions regarding their differences.
- Why would VOSviewer and CitNetExplorer yield different cluster solutions for a citation analysis (given the same dataset, the same resolution and optimization parameters and without including non-matching cited references)?
- Are there differences between the clustering techniques employed by VOSviewer and CitNetExplorer ?
- Does the former employ the Leiden Algorithm?
Thank you in advance
Rafael

Hi, and thank you very much for this software and your time to give any advice. How is lockdown for you in the Netherlands? it seems to be working for us here in Australia at present.
I'm just using VOSViewer for the first time, and trying to import my bibliographic data from my endnote library. I'm on a Mac, and my EN file names end in .enlx or .enl or .enlp . I've tried all, and either I'm told the file is empty (which I know it is not) or there is an error and, like the previous poster, 'can't find author(%A) or keyword (%K) field'. Can you advise me, please? Thanks, Rhonda

hey, and thanks for such a great software
I'm trying to conduct a co-authorship map, i have files from endnote since i used 2 different data base web of science and science direct, i export the data to txt type then i open the data in note pad and changed the extension to all files and enw extension went to VOS and i was trying the bibliographic data then data from end note then i had this error stating error while reading end note file : can't find author (%A) or keyword (%K) field
can you please tell what I'm messing here
thanks in advance

Dear Ludo Waltman,
I just make choice of co-authorship and authors,but all other options are locked.i am using scopus data in .csv file.Can you help me to resolve this problem?
Thanks in advance!

Ludo
Quick question. When conducting journal co-citation analysis is it more correct to refer to the results as "citations" or "co-citations"? For example,
a. "The Journal of Educational Psychology accrued 2,325 co-citations in the reference lists of the review documents." Or
b. "The Journal of Educational Psychology accrued 2,325 citations in the reference lists of the review documents." or
c. both are correct
Thanks.
Philip

VosViever EndNote
Some time ago a user - whom I no longer find in this conversation - suggested the following procedure:
from EndNote export txt file in "EndNote export" format
Open the txt file with notepad, save it as "all files" with the extension .enw.
Done.
This overcomes, among other things, the problem of combining references from Scopus and Web of Science although limited to Coauthorship and Keywords co-occurrence.
Hi everyone and congratulations again to Ludo and Nees Jan for the great software.

Hi,
First I would like to thank you for making the software available.
I have a problem, I have installed and re-installed several times but I cannot make the choice of "Analysis Type" because it is only locked for "Co-authorship" analysis, not allowing changes to the other analysis topics.
If you can help me I will be immensely grateful.
Att.
L. Martins

Hi, is it possible to embed somehow the interactive map to my website so I can show the network of the keywords of my publications?
Or do I need always to provide a link of the map and through that someone can check it on the VOSviewer software? I saw section 5.2 on the manual but I couldn't also understand how to make the map file online. Can you provide a different example please?
Thank you for the amazing software!

Dear Ludo Waltman,
I'm having trouble doing bibliographic coupling analysis. It only allows me the co-authorship and co-occurance tab as the type of analysis in the creating map tab, all of the data files I draw from the web of science. I'd be glad if you help. Thanks.

Is this an accurate description of 'total link strength'?
‘Total link strength’ measures the number and breadth of ‘links’ of one journal with other journals. For example, a journal with given number of co-citations could be frequently co-cited with either a smaller or larger number of other journals. This implies that a journal with higher total link strength has been co-cited with a larger number of other journals.
Thanks.

Dear Ludo,
I would like to know if there is a possibility to prevent nodes or labels from overlapping in the network view. Is it possible to make all labels apparent in VosViewer?
Thank you very much for your attention,
Lucas Carvalho

Just wondering if there's any way to increase the maximum virtual memory? I have been trying to create a map of 51,000 citations and it crashes out indicating that it run out of virtual memory. I've manually given Java 32 GB which should be plenty enough from what I can see within task manager of what It usually crashes out at around about 1 GB to 1.5. I'm assuming the restriction is within the software. The other option which I was wondering if possible was to merge smaller maps together.

hi. could you please explain to me how to use endnote data in the VOS viewer?

Dear Ludo,
First of all, I would like to thank you for the opportunity to ask questions through a direct channel. I am very interested in exploring Wikidata from VosViewer. However, I have been having difficulty finding the DOI of Wikidata articles. How should I proceed?
Thank you so much in advance.
All the best,
Lucas

Hi, please, anyone can help me, how to create a map with Endnote file? How can I prepare Endnote file? Is there any instructions with details? I have a small number of articles in an Endnote group to be analyzed. But the file type confused me. Thanks a looot!

I just wonder if VOSviewer can allow users to input additional numerical data in an extra column in the data file, e.g. Altmetric score, or score showing the location in a spectrum of basic science-applied research, etc. These data are not export-able or available in Web of Science or Scopus, but are informative.

I have a database consisting of 1,529 articles published in a single journal. When I ran journal co-citation analysis, it showed two journals with more than 1,529 citations. Is this due to those journals having multiple 'co-citations' in some of the documents?
Thanks.
Philip

Dear LudoI am working on constructing a co-occurrence network of keywords. During "Create map Wizard" I have chosen these options:1. Create a map based on bibliometric data2. Read data from bibliometric database files3. Type of analysis: co-occurrence; Unit of analysis: All keywords and Counting method: Full CountingI am trying to understand the difference between Full Counting and Fractional Counting methods in my case. I read on VOSviewer manual: Occurrences. When working with keywords, the Occurrences attributeindicates the number of documents in which a keyword occurs. When working withterms, the definition of the Occurrences attribute depends on the countingmethod that is chosen in the Create Map wizard. In the case of binary counting,the Occurrences attribute indicates the number of documents in which a termoccurs at least once. In the case of full counting, the Occurrences attributeindicates the total number of occurrences of a term in all documents. The difference between counting methods in case of co-occurrence network of terms is clearly explained. 
Furthermore I read: "Constructing bibliometric networks: A comparison betweenfull and fractional counting" by Antonio Perianes-Rodrigueza, Ludo Waltmanb, Nees Jan van Eckb. In this article there are given examples only for co-authorship, bibliographic coupling, and co-citation networks. Please can you help me understand the difference between full and fractional counting methods in co-occurrence networks of keywords?Note : I use VOSviewer version 1.6.13
Thank you in advance

Dear Ludo,
We are constructing a co-citation map with the most cited journals regarding a determined subject. When we construct this map, there are two different clusters with many journals. We are trying to understand how works the journals' classification into these two clusters. Is it based on the link strength among the journals? Citations among them?
Thank you in advance.

Dear Sir/Madam
I am trying to increase memory available to VOSViewer in the command line by using the cammand "java –Xmx4000m -jar VOSviewer.jar", but it says: "Error: Unable to access jarfile VOSviewer.jar". Could you please help me to solve the problem?
Thanks

Dear Sir/Madam,
I am trying to use the Vosviewer software for Bibliometric analysis, but each time I get a pop message that the excel file from scopus have some wrong quotes. What should I do?

Dear Ludo,
Thanks again for providing us this powerful tool.
I’m facing a problem with the bibliographic coupling analysis. When I try to model a network of bibliographic coupling generated by 6000 documents, VOSViewer pop ups an error message: “The number of clusters is too large. Choose a lower value for the resolution parameter”. I have already altered the resolution parameter to lower values (e.g. 0.1 or 0.001) but the same problem occurred. I also changed the minimum cluster size (e.g. 1000), without success.
When I model the network selecting only the giant component, this problem doesn’t appear. But for me is very important to generate a network including the unconnected items.
Thank you so much in advance.
All the best,
Antonio.

Hello,
Thank you for developing this very useful tool!
I'm conducting some analysis of data from Scopus (.csv format) and I'm getting the below error when loading multple files. Could you please advise on how can I resolve it?
Error while reading file 'scopus.csv': IOException reading next record: java.io.IOException: (line 198) invalid char between encapsulated token and delimiter.
Thanks for your answer
Diana

Dear Ludo,
Greeting for Australia. Thanks for developing this software and maintaining this page. I have a question about the termhood. I just wonder if the item relevance scores can be used as termhood value? or should I separately calculate the termhood score using, say, C-value?
thanks

Hello,
First of all, thank you for the program. While analyzing the most cited journals, I encountered the no title captured status. Is there anything I can do?

Hello,
I've only just started using this tool but I enjoy it already, thanks for the great work!
I'm trying to build a network using data from both WOS and SSRN. Is there any way to incorporate data from the SSRN database into the WOS format?
Thanks for your answer!
Sophie Korth

Hello
Seasons greetings for 2020.
I am facing a problem and hoping you have a solution for this.
1. VOSViewer produces totally different coauthor network with and without the "Reduce first names of authors to initials". Is this a bug?
2. The feature in (1) above is reducing names to single initial so introducing error in the network. For example, it takes Li, Y, Li, YL, Li, YH as one name - Li, Y.
Look forward to your help with this
Thx
Arun Saxena

Hello,
thank you for developing VOSviewer. I really enjoy using it. One question: Is it possible to show the names of all nodes in the screenshort? Can I somehow force the program to print all the names in the visualization?
If not, is it possible to tell the program which names to show in the screenshot? This would be very helpful.
Thank you and best regards!

Ludo:
I have an author co-citation map in the domain of problem-based learning that is comprised of 99 authors or a specific period of time (i.e., not the entire period of the review). In two of the three clusters, all of the scholars represented on the map are associated with 'medical education'. Of course, there were also scholars working on the design of PBL curricula in nursing, dental and engineering and management education as well. But they are not shown on the map since they did not meet the citation threshold.
I wish to name the schools of thought and am curious whether you think it is more accurate, for example, to call a school "Design of PBL Curriculum" or "Design of PBL Curriculum in Medical Education"?
Thanks.

I just started using VOSviewer and find it an amazing tool for bibligraphic network visualisation. But, when I make coauthorship network for the countries, the labels all begin with small letter. Can you please tell me how to make the Labels start with a capital letter.
Thanks.

I would like to use "corpus files" and "scores files" to create maps relating journal names and their impact factors. In “corpus files” I entered the names of the journals and in “scores files” I entered the respective impact factor. However,by generating the map, the full name of the journal does not appear, only the terms of the names. I tried to use “thesaurus file”, but I couldn't solve the problem either. Could you support me to be able to generate a map with the full name of the journals? The rest (legend according to impact factor) and circle size are correct.

Please give step by step procedure to draw network diagram of co-occurrence using Dimension database.
Thanks and Regards,

Please answer about my query. I am not getting the Web of science database.