I'm reluctant, because I don't think the discipline as a whole has many scientific merits, except for the more formal work in computer science. Anyway, here you go:
* Pragma-dialectic school (Amsterdam, F. van Eemeren) [1]
* Argumentation Schemes & Informal logic, Univ. of Windsor, D. Walton [2,3]
* Rhethorics and Argumentation, Univ. of Waterloo, C. Tindale [4,5]
* Switzerland, Lugano Group (IALS) [7]
* Lisbon ArgLab Group, New Univ. of Lisbon, M. Lewinski, F. Macagno [6]
* Germany, Research Group for Nonmonotonic Logic and Formal Argumentation, Univ. Bochum [8]
* Germany, KIT Group, Karlsruhe Institute of Technology [9]
The last two groups are more to my taste, and there is also Chris Reed and his team in the UK. The prevalent theoretical traditions are argumentation schemes and informal logic in Canada, developed by Walton and his scholars, and the pragma-dialectic tradition in Amsterdam, developed by van Eemeren and his many scholars.
* Pragma-dialectic school (Amsterdam, F. van Eemeren) [1]
* Argumentation Schemes & Informal logic, Univ. of Windsor, D. Walton [2,3]
* Rhethorics and Argumentation, Univ. of Waterloo, C. Tindale [4,5]
* Switzerland, Lugano Group (IALS) [7]
* Lisbon ArgLab Group, New Univ. of Lisbon, M. Lewinski, F. Macagno [6]
* Germany, Research Group for Nonmonotonic Logic and Formal Argumentation, Univ. Bochum [8]
* Germany, KIT Group, Karlsruhe Institute of Technology [9]
The last two groups are more to my taste, and there is also Chris Reed and his team in the UK. The prevalent theoretical traditions are argumentation schemes and informal logic in Canada, developed by Walton and his scholars, and the pragma-dialectic tradition in Amsterdam, developed by van Eemeren and his many scholars.
[1] https://gsh.uva.nl/content/research-masters/argumentation-rh... [2] https://www.dougwalton.ca/ [3] http://www.uwindsor.ca/crrar/ [4] http://www.uwindsor.ca/argumentationstudies/ [5] http://www.uwindsor.ca/crrar/ [6] https://www.arglab.ifilnova.pt/en [7] https://search.usi.ch/en/organisational-units/332/institute-... [8] http://homepage.ruhr-uni-bochum.de/defeasible-reasoning/inde... [9] http://debatelab.philosophie.kit.edu/