Getting Started

To get started with VOSviewer, you may want to take a look at some of the sources of information listed below.


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VOSviewer manual

The VOSviewer manual provides detailed and up-to-date information on the functionality of VOSviewer. The manual can also be accessed using the Manual button in VOSviewer.

Open VOSviewer manual


VOSviewer book chapter

VOSviewer is discussed in detail in a recent book chapter. The chapter provides a tutorial in which the use of VOSviewer is demonstrated in a step-by-step manner. The chapter is based on VOSviewer version 1.5.5. Some of the improvements and extensions introduced in the most recent versions of VOSviewer are therefore not covered in the chapter. In addition to VOSviewer, the chapter also discusses the CitNetExplorer tool for visualizing and analyzing citation networks of publications.

Open VOSviewer book chapter

VOSviewer paper

VOSviewer was originally introduced in a paper published in Scientometrics in 2010. In the meantime, VOSviewer has been improved and extended in many ways, so the paper is not fully up-to-date anymore. However, it still provides a useful introduction into the main ideas underlying VOSviewer.

Open VOSviewer paper

AIDA bookletAIDA booklet

The AIDA booklet introduces diverse case studies on research positioning and trend identification. These case studies are relevant for PhD candidates, researchers, group leaders, and policy makers. Many of the case studies make use of VOSviewer.

Open AIDA booklet


Mandatory fields
  • Vasiliki Vougeleka January 6th, 2022 9:54 am
    Thank you very much for this wonderful tool!
    I performed a country analysis for a peer-reviewed publication and the reviewer asked me to capitalize the countries' names. Can this be done? If not, is it somewhere written in the manual or the website to show it to him?
    Thank you!
    • Ludo Waltman January 6th, 2022 12:22 pm
      You can save your map in a VOSviewer map file, open this file in a spreadsheet program such as MS Excel, and then capitalize the country names. The country names can be found in a column with the header 'label'.
      • Vasiliki Vougeleka January 6th, 2022 12:32 pm
        Thank you for your reply and your help!
  • Josie Slaathaug January 5th, 2022 8:02 pm
    Hello, I have two questions!
    Is there a publication besides the manual that provides a concise summary of what relevance scores are based on for creating a keyword co-occurrence map?
    I'm trying to decide whether creating a bibliographic or text map better suits the keyword co-occurrences, and am wondering how those determine keywords differently? Using the same datafile, the methods vary by about 200 keywords and vary widely in the number of terms that meet the minimum threshold. Wondering how the methods differ.
    • Ludo Waltman January 5th, 2022 10:58 pm
      Maps of keywords don't use relevance scores. Maps of terms extracted from titles and abstracts do use such scores. Unfortunately, we don't have a full documentation of the algorithm used for calculating the relevance scores. The best documentation we have can be found in the following short paper:
  • Albina Krymskaya January 3rd, 2022 7:29 pm
    Hi, I have a question on harmonization of journals titles in CVC file from Scopus. If I normalize the titles, my file can't be read by VOSviewer. Would you please help to solve this problem? Thank you!
    • Ludo Waltman January 3rd, 2022 11:19 pm
      My advice is not to make any changes in CSV files exported from Scopus. This usually causes problems. Instead, you can create a so-called thesaurus file to harmonize journal titles. See the VOSviewer manual for more information about thesaurus files.
      • Albina Krymskaya January 5th, 2022 5:47 pm
        Thank you! It worked. I created a thesaurus file.
        But now there is another problem - when I create co-authorship - countries several affiliation is wrong in Scopus so CSV file has wrong information. I compared affiliation information with the paper and check affiliation.
        Example - Scopus gives 17 documents for Autralia, but the right number is 18; 108 for USA, but the right number is 107. A cited document for Australia give USA by mistake. So my question is what should I do in this situation? I guess a thesaurus file won't help in this case. If I leave it as it is then I will present incorrect information which is not good for a research paper.
        Could you please help with this?
        Thank you!
        • Ludo Waltman January 5th, 2022 11:15 pm
          That's an interesting question. Your VOSviewer map will give an accurate representation of the information provided by the Scopus database, but indeed it may not give an accurate representation of the information contained in the actual underlying research articles. I think it is important to make the distinction between these two types of accuracy.
          If your VOSviewer map doesn't give a fully accurate representation of the information contained in the research articles, I believe this is a limitation that you need to acknowledge in any paper or report in which you present the VOSviewer map. However, minor inaccuracies won't fundamentally affect your conclusions, and having such inaccuracies is almost inevitable in any data analysis of significant size, so in my view this doesn't invalidate your work.
  • Sefika January 3rd, 2022 3:53 pm
    I ran the command prompt but when I enter java –Xmx4000m -jar VOSviewer.jar
    I get an error message 'unable to access jar file VOSviewer.jar I have the latest version of Java, but I still get the same error message.
  • PhD Melike January 3rd, 2022 2:40 pm

    Dear respected Prof Ludo,
    I'm trying to analyse citations and years based on the data gathered from WOS (txt file), by VOSviewer.
    I selected" to create a map based on bibliographic data" in the next phase, I selected "read data from bibliographic database files".
    However, I can't choose citation etc. I can only choose co-authorship (I mean it's not optional). That's why I can't continue my analysis.
    Can you help me please to resolve my problem about mapping citations and other options.
    Kind regards,
    PhD Melike
    • Ludo Waltman January 3rd, 2022 3:36 pm
      When exporting data from Web of Science, it is important to choose the option 'Full Record and Cited References'. If cited references are not included in the data exported from Web of Science, VOSviewer won't be able to create a citation-based map.
  • Mell January 2nd, 2022 12:25 pm
    Hello dear respected researchers,
    Although I watched videos about VOSViewer, I could't manage to upload data from Web of Science to VosViewer software. Maybe it's so basic issue, but unfortunately I'm stuck here. Can you help me please?
    • Albina Krymskaya January 16th, 2022 9:54 pm
      Hi, if it is still interesting to you...
      You should check your language. When you exporting data from Web of Science you need to switch to English. I had a similar problem and could not understand why I could not upload to VOSViewer.
  • Catherine December 30th, 2021 4:23 pm
    Hello, again.
    I've generated co-authorship maps for authors, organizations, and countries. I've cleaned the affiliation column so that the format is "organization name, country; organization name, country". However, while my authors and countries maps are showing both nodes and lines, my organizations map is only showing nodes. Have I missed something?
    Thank you.
    • Catherine January 5th, 2022 9:46 pm
      I eventually realized that the lines weren't showing because there weren't enough links between the nodes. However, if I opted to only view the nodes with the links, the lines do appear.
  • Sefika December 29th, 2021 10:09 pm
    I ran the command prompt but when I enter java –Xmx4000m -jar VOSviewer.jar
    I get an error message 'unable to access jar file VOSviewer.jar I have the latest version of Java, but I still get the same error message.
  • Sefika December 29th, 2021 9:04 pm
    I am having the not enough memory error message. I read the manual but could not figure out where the command line is or how I can run the jar file. Could you please help? Thank you.
  • Hilda December 27th, 2021 4:58 am
    After I initially commented I appear to have clicked on the -Notify
    me when new comments are added- checkbox and from now
    on each time a comment is added I get 4 emails with the same comment.
    There has to be an easy method you can remove
    me from that service? Many thanks!
    cialis 5 mg precio en farmacia españa
    • Ludo Waltman December 30th, 2021 3:13 pm
      The emails sent to you should include an option to unsubscribe. Did you try this?
  • Sona Fathi December 26th, 2021 4:35 pm
    Hello, and I thank you for your useful software. How can I see just one cluster in the screen?
    • Ludo Waltman December 26th, 2021 6:44 pm
      I am afraid there is no easy way to accomplish this. You need to save your map in a VOSviewer map file, open this file in a spreadsheet program such as MS Excel, and delete all lines corresponding to items that do not belong to the cluster that you are interested in.
  • Kumudu December 24th, 2021 9:51 pm
    Hello Nees and Ludo,
    Thank you for this wonderful tool. I was looking if this page has a proper citation link and couldn't find it. Would you kindly share if you have a link to cite VOSviewer?
    • Ludo Waltman December 25th, 2021 8:07 am
      Thanks for asking. Most VOSviewer users cite the following paper: This is the paper in which the VOSviewer software was originally introduced.
      • Kumudu December 25th, 2021 9:22 pm
        Thank you, Ludo.
  • Viviana December 22nd, 2021 11:23 am
    Hello! First of all I would like to congratulate you for the tool and also thank you so much for letting us use it!. The programme works very well with the database I constructed to my master study. I would like to know if is it possible to take off some labels, in order to highlight the most important ones.
    Thank you in advance!
    • Ludo Waltman December 22nd, 2021 6:29 pm
      Yes, this can be done by saving your map in a VOSviewer map file, opening the map file in a spreadsheet program such as MS Excel, and deleting the labels (in the 'label' column) that you want to get rid of. When you then open your map in VOSviewer, the labels that have been deleted will no longer be visible, and this provides more space for showing the labels of other items in your map.
  • Carlos December 20th, 2021 8:50 pm
    I am trying to run it on Linux - OpenJDK 1.8.0_312. I see the screen of the application after the splash screen, but I cannot interact with the window. I can only close it. Any idea?
  • fabio freitas da silva December 10th, 2021 6:32 pm
    políticas públicas
    • ANTONIO CARLOS FREIRE ROBOREDO December 10th, 2021 6:39 pm
      quero rede bibliométrica
  • Jackie Greatorex December 7th, 2021 3:21 pm
    does this work in a language other than English?
  • Philip December 5th, 2021 12:44 am
    Two follow-up questions on the interpretation of metrics in author co-citation analysis.
    1. If Author A has 3 different publications cited in Author X's document will that count has 3 citations in the co-citation table/list generated by VOSviewer, or only as 1?
    2. The author co-citation table/list in VOSviewer shows that I have an author who has been cited 43 times in the reference lists of the documents in my database. When I click on the link between this author and another author close by, I find that the link has a strength 0f 1,806.
    I don't understand how the link strength can be higher than the number of times the author has been cited in the reference lists. This is something that has puzzled me for several years, despite reading all of the information I can find about how to interpret link strength.
    Please clarify.
    • Ludo Waltman December 9th, 2021 5:57 pm
      1. This will be counted as 3 citations, not just 1.
      2. Let me give a simple example that will hopefully clarify this issue: Suppose we have an article that cites 3 publications by author X and 2 publications by author Y. This will then yield a co-citation link between authors X and Y with a strength of 3 x 2 = 6. This reflects the fact that there are 6 co-citation links between a publication by author X and a publication by author Y.
  • Philip December 4th, 2021 2:41 pm
    Assume that I have an author co-citation map with a threshold of 25 citations, display of 75 authors, and four clusters on the map. Two scholars each have more than 25 citations (co) and have links to all four clusters. However, they are located far away from all other authors and clusters on the map. Moreover their affiliation is with a cluster located on the opposite corner of the map.
    What is it about their co-citation pattern by other scholars that locates them as outliers at such a distance from all other authors on the map?
  • analytics December 4th, 2021 9:25 am
    Dear Sir/madame
    I would like to visualization a map by Wikipedia. Can you help me?
  • Maria Calvo Uyarra December 4th, 2021 2:07 am
    Thank you for the software! it is great.
    I have a problem in trying to get my thesearus right. It indicates that "a label cannot be both in the LABEL column and in the REPLACE BY column. It provides me the line where the problem is found. So for example in my label coloum I have "Acropora" and my replace by says "coral species". Yet, it indicates that it is the same label. If i decide not to replace, it allows me to move forward, but it indicates that I have the same problem with another line. Could you indicate me where can be the problem?
    Thank you
    • philip December 5th, 2021 8:21 am
      You have inadvertently included either Acropora or coral species in both columns. Use cntrl F to search each column for both terms until you figure out which keyword is duplicated. Then fix it so that neither of the terms is in both column A and B.
      My suggestion.
  • giuseppe vito December 1st, 2021 1:12 pm
    Hi, Ludo, glad to find you again. In a map of a corpus file (without a score file) what is the meaning of the links between two terms?
    • Ludo Waltman December 1st, 2021 6:42 pm
      It is the number of co-occurrences of two terms, so the number of documents (i.e., lines in your corpus file) in which both terms occur.
  • Katie December 1st, 2021 8:02 am
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    ________ ___-__ _________ ___ _________ _ ________, ___-__ __ _____________
    _________, _ _____ ______ ___________
    _ __________ _ ______ __ ____, _______ __________ ___ _____.
    ___ ______________ _________ _ _________ _____________ _____ _________ ______ ____
    _____, _____ ___ __________ ________ ______ _ ________ _________ __________ ____________.
    _________ _______ ________ ______ _________ ________, __ _______ ____ __ _________ _______ _____.
    ___________ _____________ _
    _____ ______ _ ________ __ ______ ______,
    _ _____ ________, __ __ __________.
  • Shahid Rasool November 29th, 2021 9:36 am
    Dear Admin,
    I want to extract data of Scopus database but when follow your tutorial that is link of www.webofknowledge.come but that is not going to open same website as you are shown in your instruction video. Kindly help me how I can extract data for using VOSviewer software.
    Shahid Rasool
    • Sona Fathi December 26th, 2021 4:42 pm
      in scopus, choose all papers then click the export then click all part then choose csv file and finally export. then you can use that csv file in vosviewer.
  • Shubham Singhania November 29th, 2021 8:11 am
    I am using Vos-viewer for Citation and Co-cittaion analysis, it is not shwoing the tab for citation and co-citation analysis.
    Can someone Please help what could be the issue and how this can be resolved
  • Liuyong Ding November 29th, 2021 5:44 am
    What can vosviewer be used for in Java?
    "java -jar VOSviewer.jar -map MappingFileRes2.27_overlay.txt -overlay_visualization -max_label_length 0 -scale 0.5 -save_screenshot_emf cluster6.emf"
    but, How do I get the parameters of vosviewer, such as -map or -overlay_visualization?
  • 杨增增 November 28th, 2021 3:10 am
    I want to learn the VOSviewer.
    • Sona Fathi December 26th, 2021 4:46 pm
      I learn it from YouTube and also can help you.
  • Manuel Vidal Jr November 27th, 2021 11:55 pm
    Hi, thank you for making this software! I have a question regarding co-occurrences; I am currently doing an analysis of genes studied for the past decades. For instance, in my analysis output, the keywords "ace" (angiotensin converting enzyme) and "ace gene" appear as separate entries with separate relevance scores. Is there a workaround in which I can combine these two entries with a single relevance score (because they are most likely talking about the same thing, that is, the ace gene)?
    Thank you!
    • Ludo Waltman November 28th, 2021 5:31 pm
      Yes, this can be done using a so-called thesaurus file. Please see the VOSviewer manual for more information about thesaurus files.
  • Paulo Nuno Vicente November 26th, 2021 3:33 pm
    I have exported the RIS and EndNote files of a sample of 13 scientific articles that I would like to analyze. When using VOSViewer version 1.6.17, the option is only provided to analyze the "title" field and not, as I would like, the "title and abstract". Is there a setting that allows this? Thank you so much for this great tool and your support
  • C Jimenea November 26th, 2021 6:50 am
    Thank you for the very quick response!
    I was actually trying different export file formats that WoS and Scopus both had. RIS is one such common format, but it only produced co-authorship and co-occurrence analyses, despite opting to export all details of each reference. And it doesn't matter if I only use the RIS file from Scopus, from WoS, or from both. However, if I use the bibliographic dabase files of WoS and Scopus, either provide options for the five types of analyses. Am I doing something wrong and/or is there a workaround for RIS to get the other three types of bibliographic data analyses?
    • Ludo Waltman November 27th, 2021 4:21 am
      Unfortunately the functionality that we are able to provide in VOSviewer for creating maps based on RIS files is quite limited. In particular, VOSviewer is unable to create citation-based maps based on RIS files. While RIS files may contain reference data, this data doesn't have a standardized format. Therefore VOSviewer is unable to process the data.
      • C Jimenea November 27th, 2021 4:36 am
        Okay. Thank you, again, for your quick response. And thank you for providing the research community with a very interesting tool.
  • C Jimenea November 25th, 2021 5:58 pm
    Is there a way to merge the exported results from WoS and Scopus into VOS? I have references that show up in one but not the other so I'd like to combine both.
    Thank you.
    • Ludo Waltman November 26th, 2021 12:53 am
      I am afraid there is no easy way to accomplish this. The file formats used by Web of Science and Scopus are quite different, making it highly challenging to combine data from these two databases.
    • Sara Larrabure January 24th, 2022 4:43 pm
      I'm having the same problem joining the two databases. How did you solve the problem?
  • Josie November 14th, 2021 8:01 pm
    Hello, I have two questions!
    Is there a publication besides the manual that provides a concise summary of what relevance scores are based on for creating a keyword co-occurrence map?
    I'm trying to decide whether creating a bibliographic or text map better suits the keyword co-occurrences, and am wondering how those determine keywords differently? Using the same datafile, the methods vary by about 200 keywords and vary widely in the number of terms that meet the minimum threshold. Wondering how the methods differ.
  • Racliffe Lai November 10th, 2021 9:16 am
    I am trying to use OpenRefine to curate the similar words. From the suggested manual, I have learnt how to do the curation in the column of keywords in a Web of Science file. However, I actually would like to include the information from abstract too.
    Is it possible that I do the curation after VOS Viewer has identified the words for analysis, i.e. the list VOS Viewer displays after counting the occurrences. I noticed that I could export the list but do not know if there is a way to import it after the curation.
    Thanks a lot.
    • Ludo Waltman November 10th, 2021 2:33 pm
      To identify and merge related terms occurring in titles and abstracts of documents, my advice is to create a thesaurus file. See the VOSviewer manual for more information about thesaurus files.
      • Racliffe Lai November 13th, 2021 11:06 am
        Thank you for your prompt reply!
  • Sona Fathi November 6th, 2021 10:42 pm
    how can I export cluster items (items of each cluster separately)?
    • Ludo Waltman November 7th, 2021 10:38 am
      You can save your map in a VOSviewer map file. This is a plain text file that can be opened in a spreadsheet program such as MS Excel. The information you need can be obtained from the map file.
  • Julia Naranjo November 3rd, 2021 11:18 pm
    Does vosViewer use first author, matching author, or all authors for ACA?
    The bibliometric analyzes that use Bibliometrix (R) and Vosviewer at the same time, are they based on different information for the analysis of authors?
  • Peter November 3rd, 2021 1:33 am
    I conducted an author keyword co-occurrence analysis. I understand the 'occurrence' of an item refers to the frequency of the keyword that appears in the corpus. The 'link' of an item refers to the number of co-occurrence of that particular word to other words in the corpus. But I'm not quite sure how to interpret the 'total link strength' of a particular item. I checked the manual and online but still won't be able to find an answer for this. I would be much appreciated if you can give me a hand on this.
    • Peter November 3rd, 2021 3:37 am
      BTW, I'd read the post by Toshiyuki Hasumi below and checked the manual as well. But I'm still not too sure how to understand total link strength in keyword co-occurrence. Any further explanation/help is much appreciated.
    • Josie November 11th, 2021 8:33 pm
      Hi Peter,
      I just did some thorough research on this and came up with the following explanation:
      Each link has a strength associated with it that refers to the number of publications in which the terms occur together. The total link strength of an item (keyword) is the sum of all of it's individual link's link strengths.
      For example, keyword A has 2 links, link to term B (strength 3) and link to term C (strength 4). The total link strength for keyword A is 7.
      • Ludo Waltman November 11th, 2021 11:42 pm
        Thanks Josie, your interpretation of total link strength is indeed correct.
        • Peter November 12th, 2021 1:38 am
          Hi Josie and Ludo,
          Many thanks for the explanation. I see what it means now. Much appreciated for the help!
      • Junaid December 29th, 2021 12:12 pm
        Hi Josie,
        I tried co-authorship visualization but I found an issue. Few of the author nodes are part of a cluster (because of the same color) but they're not connected to any other node in the cluster.
        For example, an author has link strength 5 and the number of documents as 2 but it is still not connected to any other author.
        Would you have any idea about why is that happening?
        • Ludo Waltman December 29th, 2021 1:20 pm
          If authors belong to the same cluster, there should be connections. Perhaps some of the connections are not shown by VOSviewer. You may need to increase the number of lines that VOSviewer shows.
          • Junaid December 29th, 2021 2:07 pm
            Worked fine! Thank you so much :)
  • Sefika October 30th, 2021 10:06 pm
    I have run the citation for countries for 1864 documents exported from Scopus. The results I get from VOSviewer gives me the distribution for 1710 documents. I tried with other exported documents and the result is the same - the number of documents I get from VOSviewer is less than the number exported. Is there any explanation for this?
    • Ludo Waltman October 31st, 2021 8:39 pm
      I don't think I fully understand your question. Could you let me know where you found the number of 1710 documents in the user interface of VOSviewer?
      • Sefika October 31st, 2021 9:52 pm
        The number of the documents I exported from Scopus was 1864. I uploaded it to VV to create a citation-based map of countries and to analyze the geographic distribution of the publications & citations. The list of documents by country generated by VV where it asks to verify selected countries (just before the map) adds to 1710 documents and the map is based on 1710 documents.
        • Ludo Waltman November 1st, 2021 9:35 am
          Thanks for clarifying. I think there's no reason to be concerned about this. Some countries probably have been filtered out (since VOSviewer by default includes only countries with a certain minimum number of documents). Also, there may be documents without affiliation/country data, so these documents cannot be used in a country-level analysis.
  • irfani ahmad October 29th, 2021 4:47 pm
    I want to try it, hopefully it can be a solution to my problem
  • Michael S Mendez October 26th, 2021 3:39 pm
    It's my first time watching a video about VOSviewer as I find bibliometric analysis fascinating. Thank you for creating this tool so all the curious souls in the world can have a tool to understand and present text data with ease.
    I'm delighted also to know that the software is for free.
    This is awesome!
  • mr KIM October 12th, 2021 6:05 pm
    I try to visualize countries unfortunately this function is switched off and I could not press the "countries" button
    thank for advice
  • Jong-Hwan Lee October 11th, 2021 11:58 pm
    VOSviewer + CitNetExplorer
    Quick question regarding using both tools: when I read your paper (van Eck and Waltman, Scientometrics, 2017), you showed a great utility of using both tools. However, I did not fully understand how you did to get Fig. 3 using VOSviewer visualization from the 22 clusters obtained from CitNetExplorer. I assumed that you'd performed the clustering using CitNetExplorer and then exported/input the resulting clusters to the VOSviewer, right?
    In the Conclusion section of the paper, you described that "However, the combined use of the two software tools is somewhat laborious, and preparing the input data for VOSviewer based on the clustering results provided by CitNetExplorer is not entirely straightforward."
    I wonder whether there is any procedure/steps for me to follow to perform the function you showed in this paper (mainly, clustering of individual publications using CitNetExplorer followed by keyword analysis/visualization in an aggregate level using VOSviewer).
    I guess the procedure is something like: (1) export clustering results as some sort of network file) from the CitNetExplorer and (2) open the clustering results along with bibliographic files (with title and abstract) in VOSviewer to visualize/analyze keywords.
    I believe knowing the procedure of how to do this will significantly enhance the utilities of both tools.
    I am looking forward to having feedback, and thanks very much for developing these great tools!
  • Bi Chen October 10th, 2021 4:39 am
    When I analyze the Chinese database, I import the network generated by vosviewer into pajek and rearrange it. When I import vosviewer again, the Chinese code is garbled. How to solve?
  • manoranjan dash October 8th, 2021 5:55 pm
    I am not able to work on Bibilography coupling and co-citation with Scopus data .
    This option is not being highlighted
    How the problem can be solved
    • Ludo Waltman October 9th, 2021 11:03 pm
      When exporting data from Scopus, make sure to include all data elements, in particular the references.
  • THEODORA VAGDATLI October 5th, 2021 7:01 pm
    Good afternoon,
    I would like to ask something about the usage of "thesaurus_file" during a VOSviewer visualization based on "text-data" and "title and abstract fields" extraction of knowledge.
    I used the "thesaurus_file" for both ignoring some generic terms and replacing some other with something else.
    I realized that the new map also lacked the terms I wanted to ignore and the terms I wanted to replace with another term.
    Is there any explanation for this?
    Or is there anything I can do about it?
    Your answer would be valuable for my academic research into my field.
    Thank you in advance.
  • George October 5th, 2021 12:15 am
    How does Vosviewer seperate country and organization when the input is csv data from Scopus? My problem is that by my co-authorship map of countries i also see organizations.
    • Ludo Waltman October 6th, 2021 1:08 pm
      VOSviewer takes an algorithmic approach to separate countries and organizations in affiliation strings in CSV files exported from Scopus. The algorithm makes use of the fact that the last part of an affiliation string typically refers to a country. Unfortunately, however, this doesn't always yield correct results, so in some cases the algorithm may fail to separate countries and organizations in a correct way. You may then consider the use of a thesaurus file to perform some further data cleaning (see the VOSviewer manual for more details).
  • IMOLEAYO AWODELE October 4th, 2021 7:14 pm
    Dear Ludo Waltman,
    I was amazed at this wonderful tool you created. You just safe a soul and many more who will find out about this incredible software!
    Reading through the comment box was superb as you took time out to provide answers to every query raised.
    Thanks for doing this great job; attending to query and questions!
    I just heard about the VOS yesterday, how do I get register for training on the usage?
    Though someone mention in the comment box about tutorial clip.
    Thank you
  • Philip September 27th, 2021 1:16 pm
    In brief, as a user of VOSviewer hat are the value-added features of Cite Explorer?
  • Dung Vu September 27th, 2021 12:06 pm
    Good afternoon!
    I thank you a lot for providing us a very helpful tool for bibliographic visualization. My question is that when I imported a thesaurus file for keyword co-occurrence visualization map, the program informed that "Error while reading VOSviewer thesaurus file (line 1): Column header is empty". I have created my thesaurus file in Excel, had columns' headers as "label" and "replace by" and saved it as a CSV or TXT file. Could you please tell me what can I do to deal with this error, if you do not mind? I thank you very much for your support.
  • Antonis Pavlozas September 16th, 2021 6:00 pm
    I wanted to ask what is the difference of total strength link and the occurence that exist at the end of every network.
  • Josephine Slaathaug September 10th, 2021 8:28 pm
    Good afternoon,
    A few simpler questions about the resulting visualization output:
    -What do the lines represent?
    -How does the program determine which keywords to connect?
    -When the maximum # of lines is adjusted, how does the software decide which lines to remove?
    Thank you,
  • Andy Yeung September 8th, 2021 8:58 am
    Hi Prof Waltman,
    I downloaded the latest version of 1.6.17 and downloaded data from Lens to try it out. I found that using Bibliographic data, Organizations and Countries were not among the available options for Co-authorship and Bibliographic coupling. I checked the csv file and these fields were present in the data. Any steps did I miss? Thank you for your help.
    Best regards,
    • Ludo Waltman September 9th, 2021 8:14 am
      Could it be that you have exported data for patents from the Lens instead of data for scholarly works?
      • Andy Yeung September 10th, 2021 10:04 am
        I confirmed that I exported data from Scholarly works. And I am using Mac version of VOSviewer.
        • Ludo Waltman October 6th, 2021 9:10 am
          Andy, are you sure your CSV file includes organization and coutry affiliation data? I don't think this data is included in CSV files exported from the Lens. (These files do include a 'source country' column, but this refers to the country of the journal.) Because CSV files exported from the Lens don't include organization and coutry affiliation data, VOSviewer is unable to create bibliographic coupling maps based on organizations and countries.
          • Andy Yeung October 21st, 2021 4:30 am
            Now I understand... I was confused by 'source country' column. It is a pity that data from Lens is incomplete. I will then stick to WOS and Scopus. Thanks!
    • George October 5th, 2021 11:39 am
      Same problem for me
      • Ludo Waltman October 6th, 2021 9:12 am
        Please see my above response to Andy.
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