Error message

  • Notice: Undefined variable: _SESSION in tracking_init() (line 27 of C:\xampp\htdocs\rsds\sites\all\modules\rsds\tracking\tracking.module).
  • Warning: file_get_contents(http://user-agent-string.info/rpc/get_data.php?key=free&format=ini&ver=y): failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in UASparser->get_contents() (line 247 of C:\xampp\htdocs\rsds\sites\all\modules\rsds\tracking\UASparser\UASparser.php).
  • Warning: file_get_contents(http://user-agent-string.info/rpc/get_data.php?key=free&format=ini): failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in UASparser->get_contents() (line 247 of C:\xampp\htdocs\rsds\sites\all\modules\rsds\tracking\UASparser\UASparser.php).

Pawlak Number of the First Kind

The Pawlak number nP of an author is defined as follows:

  • Pawlak himself has nP = 0
  • People who have written a joint paper with Pawlak have nP = 1
  • Their coauthors, with the Pawlak number not defined yet, have nP = 2, etc.




Please insert your surname and first name to check your Pawlak number.




Text files including the Pawlak numbers from 1 to 13 are available for downloading. Just click on any icon below to download a file that includes authors for specified Pawlak number.




We need the close cooperation of the rough set community to keep these data as accurate as possible, so please notify us of any errors we have made.