1 Short title: Delphi survey on quantifying bilingual experience Full title: How to quantify bilingual experience? Findings from a Delphi consensus survey Author names and affiliations: 1. Cécile De Cat, University of Leeds 2. Draško Kašćelan, University of Leeds 3. Philippe Prévost, Université de Tours 4. Ludovica Serratrice, University of Reading 5. Laurie Tuller, Université de Tours 6. Sharon Unsworth, Radboud University 7. The Q-BEx Consortium* *The Q-BEx Consortium: Nouhad Abou Melhem, Ashley Adams, Eva Aguilar-Mediavilla, Nadia Ahufinger, Shanley Allen, Llorenc Andreu, Effrosyni Froso Argyri, Sharon Armon-Lotem, Jacqueline Arsenault, Heather Baer, Colin Baxter, Lisa Bedore, Elma Blom, Mirjam Blumenthal, Ute Bohnacker, Claudine Bowyer-Crane, Krista Byers-Heinlein, Allegra Cattani, Shravasti Chakravarty, Vicky Chondroggiani, Dayna Camilleri Clarke, Joanne Cook, Daniel Cubilla-Bonnetier, Ineta Dabasinskiene, Kankan Das, Rachael Davis, Angela de Bruin, Annick De Houwer, Martine Diab, Maaike Diender, Helen Drummond, Heli Elovaara, Victoria Farrell, Karina Fascinetto- Zago, Giulia Filippi, Caroline Floccia, Max Freeman, Silke Fricke, Margaret Friend, Carolyn Gelenter, Samina Ghafoor, Kleanthes K. Grohmann, Matt Hall, Ewa Haman, Cornelia Hamann, Riikka Härkönen, Jeni Harrison, Carly Hartshorn, Maha Hassan, Erika Hoff, Nayr Ibrahim, Sladjana Indjin, Katy Isaac, Susan Joffe, Holly Joseph, Maria Kambanaros, Kathryn Kashyap, Olga Kepinska, Andrea Kewin, Ekaterini Klepousniotou, Tanja Kupisch, Francesca La Morgia, Gabrielle Lai, Nienke Lam, Jane Le Roux, Mia Le Roux, Annina Manninen, Virginia Marchman, Theodoros Marinis, Prisca Martin, Lourdes Martinez Nieto, Chantal Mayer-Crittenden, Natalia Meir, Liz Metcalfe, Eléonore Morin, Lina Mukhopadhyay, Victoria A. Murphy, Vishnu KK Nair, Marie Newton, Arja Nieminen, Silvia Nieva, Audrey Noel, Ewelina Urszula O'Donnell, Therese O'Sullivan, Ciara O'Toole, Weronika Ozpolat, Felicity Parry, Michelle Pascoe, Rupam Patel, Vrishali Patil Ingle, Sean Pert, Anne-Gaelle Piller, Eva Poort, Christine Potter, Eveliina Rantanen, Saiqa Riasat, Lidia Rodriguez, Wiebke Scharff Rethfeldt, Bethany Faye Schwartz, Irina Sekerina, Miquel Serra Raventós, Saleh Shaalan, Jinder Singh, Beth Skelton, Vicky Slaughter, Anne Margaret Smith, Sini Smolander, Neal Snape, Marina Sokolova, Antonella Sorace, Lisa Spinney-Hutton, Frances Jane Stokes, Luke Swift, Vasim Salim Tamboli, Elena Theodorou, Elin Thordardottir, Ianthi Tsimpli, Rachael Tuckley, Olga Urek, Liza van den Bosch, Klarien van der Linde, Laetitia Vanbruwaene, Josje Verhagen, Virve Vihman, Adriana Weisleder, Gillian Wigglesworth Address of correspondence: Cécile De Cat, University of Leeds, Michael Sadler Building, Woodhouse, Leeds LS2 9JT, United Kingdom; c.decat@leeds.ac.uk