Abstract Interactive digital narratives (IDNs) create alternate realities using both fictional and non-fiction material. The interactive aspect of IDN turns audiences into participants and enables the exploration of alternative perspectives and actions within a single artifact. Such multifaceted representations make IDN a vehicle for representing complex issues, a crucial capability at a time when the limits of traditional narrative media to adequately represent complex issues such as climate change become apparent. Conversely, properly evaluated, generalized knowledge about how exactly IDNs engage and influence us and what this means for the design of such works is still scant and thus this topic needs scholarly attention. In this overview paper, we discuss the potential of IDN, but also the difficulties of realizing this potential in terms of design and of verifying the effectiveness through empirical research methods. The potential of IDN as dynamic, participatory, and encyclopedic artifacts can be clearly expressed, yet the same cannot be said when it comes to the design and especially the evaluation of intended prosocial effects, the topic this paper is focused on. We start by identifying the problem of IDN design resulting from a combination of the lack of generalized knowledge and formal professional training. Then, we discuss the challenge of measuring the effectiveness of IDN design for prosocial effects and report on several case studies. In this context, we discuss methodological issues and advocate for best practices. Finally, we consider future steps in addressing the continuing challenge of evaluating IDNs.

In this paper we present the design process of a virtual reality experience the aim of which is to have a restorative effect on users. In the simulated natural site, the user can interact with some elements of the environment and can also explore the view. We describe how we tried to create a more realistic sense of nature by relying on high quality graphics, the use of free-roaming space, and naturalistic interactions. During the design process we avoided gameful interactions and instead created playful interactions, while also relying on the multimodal aspect of the virtual reality technology.

Through interaction with the virtual environment and virtual characters, users are able to influence the storyline of many games. The design choice for the style of interactivity can thereby have a crucial influence on the user's experience. However, only a few approaches evaluate different interaction modalities for one system to investigate the impact of design choice on the users' experience. In this paper, we present an experimental approach in which we first reflect on design alternatives concerning a specific element of interactive narratives-user-character dialog-and then investigate user responses to different design options (round-based dialog versus continuous dialog). Results of an experimental evaluation study show that users tend to prefer continuous interaction in a soap-opera-like game environment using typed text input to communicate with virtual characters that act and react using speech output, although the recognition rate of user utterances of the continuous version was slightly worse compared to the round-based version.