*Dear SigDial community,* We are excited to invite you to our workshop DEBP-PVA: Designing and Evaluating Behavioural Paradigms With Proactive Virtual Agents. This a workshop of IVA 2025 taking place in Berlin, Germany on September 16th. DEBP-PVA examines the design and evaluation of behavioural paradigms that effectively elicit and measure proactive behaviour in Intelligent Virtual Agents (IVA) research. Current paradigms focus mainly on agent behaviour. However, it remains unclear how these paradigms effectively help to elicit and measure proactive agent interactions and produce ecologically valid data, particularly for the paradigms that promote the use of different modalities during interaction beyond text or speech. We aim to bring together researchers to discuss methodologies for developing tasks that not only structure agent behaviours but also provide meaningful insights into the social and cognitive processes involved in proactive interactions. We invite researchers to contribute 2-4 pages long (including references) papers that include position statements, literature reviews, or in-progress empirical studies. We are especially interested in short position papers that make an argument for a viewpoint or perspective to advance the current research landscape of the design and evaluation of behavioural paradigms of IVAs in proactive scenarios. All accepted papers should be prepared in the “ACM Standard” format, more specifically the “SigConf” format (see instructions for the IVA full papers: https://iva.acm.org/2025/call-for-papers/). Submission will be made in EasyChair using the link: https://easychair.org/conferences/?conf=debppva25. Visit our website <https://sites.google.com/view/debp-pva2025/home?authuser=0> for full information about the workshop. Suggested workshop topics may include, but are not limited to the following areas: - Design and evaluation of experimental tasks (behavioural paradigms) that effectively elicit and measure proactive behaviour in IVAs - Behavioural paradigms and methodologies are best suited to evaluate proactive interactions within realistic settings - How can gaze, motion, speech, and other multimodal cues be leveraged to both trigger and evaluate proactive agent behaviour? - Challenges when evaluating the fidelity of proactive behaviours within ecologically valid paradigms. - Key differences between proactive behaviour as intended in paradigms versus how it manifests in real-world scenarios. *Keywords: * Intelligent Virtual Agents (IVAs), Proactive Behaviour, Behavioural Paradigms, Evaluation Methods, Multimodal Interaction, Ecological Validity, Task Design, Measuring Proactivity *Important dates (AoE):* - Submission deadline: June 23th, 2025 - Notification of acceptance: July 4th, 2025 - Camera-ready versions for inclusion in proceedings: 28th of July - Workshop: September 16th, 2025 Organizing committee: Alafate Abulimiti, Paola R. Peña, Guy Laban, Tanja Schneeberger, Jairo Pérez-Osorio, Tobias Thejll-Madsen, Nima Zargham, Smit Desai, Justin Edwards, Matthias Kraus, Shashank Ahire, Fatemeh Alizadeh, Yuan He, Alberto Jovane, Darragh L. Higgins, Jaisie Sin, Heloisa Candello, Rachel McDonnell, Benjamin R. Cowan