The Theory Group takes care of the substantive issues in the questionnaire. The members critically evaluate the existing questionnaire and prepare proposals for improvements, new topics and issues to be included and items and questions to be dropped. Further they initiate publications and make proposals for meetings/seminars/congresses and sessions at existing congresses.
| Chair |
| Paul de Graaf |
| Secretary |
| Loek Halman |
| Members |
| Ola Listhaug |
| Ladislav Rabusic |
| Etienne Schweisguth |
| Jorge Vala |
| Malina Voicu |
| Associate members |
| Gordan Crpic |
| Aleksandra Jasinska-Kania |
| Patrizia Venturelli Christensen |