You can use VosViewer in 2 ways:
from your web browser - it is best NOT to use Chrome. Ensure you have Java installed.
OR
download the program to your PC, check you have Java installed and then load the VosViewer program
Two options to get OpenJava (OpenJDK), that have been suggested by previous course members, f you do not have fee-based Oracle Java (needed for VosViewer):
1. Zulu Open JDK (includes installer)
Select Java Version, Operating System and Architecture and download, then install.
OR
2. jdk.java.net (no installer)
Open VosViewer online and select LaunchVosViewer button (on the left of the screen)
Open the java download (click on jnlp file)
OR
Open VosViewer on your PC
Carry out a search in the PubMed or Web of Science or Scopus. A suggested search in PubMed is shown in the right hand of this screen.
Download the search results to your desktop.
In VosViewer
Select Create from the Map menu
Select Create a map based on text data
Click Next
Select Read data from bibliographic database files
Select the database tab e.g. PubMed
Load the file you have saved to the desktop
Select Next
Select title and abstract fields and click Next (please note sometimes the PubMed file does not load first time)
Choose full counting and click Next
Change the Minimum number of occurrences of a term to 5 and click Next
When Number of Terms to be selected is displayed click Next
Once the Term list displays click Finish
Please note that cluster numbers will vary each time you do a search and cluster colours may vary (unless you save the map at the time you do the search).
We can see that there are many themes in this literature.
'Catheter' can be seen in one group - but clearly there is a lot more going on in this result set than catheters.
To start to see what the themes are click on the Items tab in the left hand menu.
Type in the word 'cap' and you will see how the word 'cap' features in each of the clusters.
Clearly a lot of these clusters are not relevant to catheter caps - which really only features in one cluster. So this can show how much noise is caused by 'caps' searched for alone. So maybe searches need to be linked to other terms such as 'catheter'
If you check out the search term in Items, you can look at the full list of terms in one of the clusters. Even within the specific cluster that does relate to catheter caps, you will see some non-relevant use of 'caps'.
Concepts that are not closely related to the catheter cluster will be far away. So if you search the distant clusters you will find one which contains the word 'pig'. This can be seen to relate to pig farms.
Save the map for later by selecting the File tab and then choosing Save.
Save your work as a VosViewer map file. Then you can load it again if you want to review it.
To learn more about VosViewer click on the Manual in the left hand options.
How effective are catheter caps at reducing infections?
Search for (cap OR caps) AND infection*
Limit the results to 2018-2020
Click on Save
Select All results
Select Format PubMed
Click on Create File
Save the file to the desktop