Main Path Analysis
Main path analysis was first proposed by Hummon and Doreian. It is a mathematical tool to identify the major paths in a citation network, which is one form of a directed acyclic graph (DAG). The method begins by measuring the significance of all the links in a citation network through the concept of ‘traversal count’ and then sequentially chains the most significant links into a “main path”, which is deemed the most significant historical path in the target citation network. The method is applicable to any human activity that can be organized in the form of a citation network. The method is commonly applied to trace the knowledge flow paths or development trajectories of a science or technology field, through bibliographic citations or patent citations.
–Wikipedia
Tools
Pajek
CitNetw
isi
Steps
1. Download the data from Web of Science following Save to other format>Full record and cited references>Plain text.
2. Merging downloaded ISI data files (tagged format from marked list) into a single file “data.txt”(Suggested by Hamid Jamali, July 2, 2009.)To use the software with ISI data, you need to download the data from the marked list of ISI in tagged format. ISI allows you to download up to 500 records each time. If you want to download more than 500 records you need to download them in several 500-batches and then combine them into a single file. Here is a simple method for doing that.
1) Put all the files in a single folder and name them in the sequence you want their data to be added to the end of each other, like 01.txt, 02.txt, 03.txt and so on. So the content of 02 will be copied at the end of 01, then the content of 03 will be copied to the end of the 01&02, and so on.
2) Open each file with notepad and delete “EF” (which marks the end of the ISI data file) from their end (except the last one) and “FN ISI Export Format VR 1.0” (which marks the beginning of the ISI data file) from their beginning (except the first one). Just remember not to leave extra paragraph marks (Enter) in the files.
3) In windows, go to run command (in start menu) type cmd and run, then use CD (change directory command) to go to the folder where you have saved the data. Then run “copy *.txt data.txt”. This command reads the content of all txt files in the folder and copies them in a single file named data.txt
Be aware that at the beginning of each file ISI inserts two invisible characters. The first lines of each download file should therefore not be removed.
3. Use isi to process data.txt into a format for relational database management.
4. Use CitNetw to generate lcs.net which contains a matrix with the citing documents in the rows and the cited ones in the columns.
5. Main path analysis with Pajek
1) Network > Open the generated .net file
2) Select the largest connected component of the network for main path analysisNetwork > Create partition > Component > Weak (1)Check the Network Info to id the largest component, usually Cluster 1 or Cluster 1-3
Operations > Network + Partition > Extract subnetwork (Cluster id)
3) Shrink strong components in the selected largest component
Network > Create partition > Component > Strong (1)
Operations > Network + Partition > Shrink network (accept default values)
4) Remove loops (if any)
Network > Create new network > Transform > Remove > Loops
5) Create main path (or critical path)
Network > Acyclic network > Create weighted > Traversal > SPLC (Diana Lucio-Arias &. Loet Leydesdorff, 2008)
Network > Acyclic network > Create (Sub)Network > Main Paths > Key Route (1-10)
6) Draw the resultant main path
Macro > Play (LAYERS.MCR)
References
https://en.wikipedia.org/wiki/Main_path_analysis
https://www.leydesdorff.net/software/citnetw/
https://www.leydesdorff.net/software/isi/index.htm
http://blog.sciencenet.cn/blog-554179-1075142.html