Understanding user enjoyment is crucial in human-robot interaction (HRI), as it can impact interaction quality and influence user acceptance and long-term engagement with robots, particularly in the context of conversations with social robots. However, current assessment methods rely solely on self-reported questionnaires, failing to capture interaction dynamics. This work introduces the Human-Robot Interaction Conversational User Enjoyment Scale (HRI CUES), a novel 5-point scale to assess user enjoyment from an external perspective (e.g.by an annotator) for conversations with a robot. The scale was developed through rigorous evaluations and discussions among three annotators with relevant expertise, using open-domain conversations with a companion robot that was powered by a large language model, and was applied to each conversation exchange (i.e.a robot-participant turn pair) alongside overall interaction. It was evaluated on 25 older adults' interactions with the companion robot, corresponding to 174 minutes of data, showing moderate to good alignment between annotators. Although the scale was developed and tested in the context of older adult interactions with a robot, its basis in general and non-task-specific indicators of enjoyment supports its broader applicability. The study further offers insights into understanding the nuances and challenges of assessing user enjoyment in robot interactions, and provides guidelines on applying the scale to other domains and populations. The dataset is available online.

Global inequalities in access to essential resources such as education, healthcare, and technology continue to widen social and economic disparities, especially in underserved and underrepresented communities. The growing integration of foundation models and other machine learning systems in robots offers promising and personalized solutions that can adapt to various individuals, situations, and environments, potentially addressing some of these gaps. By learning from interactions and evolving with local conditions, these systems can provide individualized support, such as assisting older adults with daily tasks, aiding children with special needs in learning environments, or empowering people with disabilities to live more independently. Building trust and fostering collaboration between humans and robots will help ensure that these systems meet the unique needs of all individuals, especially within long-term human-robot interaction (HRI). With this year's theme of “Overcoming Inequalities with Adaptation”, in line with the overall theme of the conference “Robots for a Sustainable World”, the fifth edition of the ”Lifelong Learning and Personalization in Long-Term Human-Robot Interaction (LEAP-HRI)”l workshop aims to bring together insights across diverse disciplines, exploring how continually evolving robots can effectively operate in diverse environments, promoting greater equity, inclusivity, and empowerment for individuals and communities. The workshop aims to facilitate collaborations across diverse scientific perspectives through a keynote presentation, panel discussions, and in-depth discussions on the contributed talks, attempting to shape a more sustainable and equitable future through adaptive advancements in long-term HRI.

As we move toward a future where robots are increasingly part of daily life, the privacy risks associated with interactions, particularly those relying on cloud-based large language models (LLMs), are becoming more pressing. Users may unknowingly share sensitive information in environments, such as homes or hospitals. To explore these risks, we conducted a study with 39 native English speakers using a Furhat robot with an integrated LLM. Participants discussed two moral dilemmas: (i) dishonesty, sharing personal stories of justified lying, and (ii) robot disobedience, discussing whether robots should disobey commands. On average, participants disclosed personal stories 45% of the time when asked in both scenarios. The main reason for non-disclosure was difficulty recalling examples quickly (33.3-56%), rather than reluctance to share (7.2-16%). However, most participants reported a lack of discomfort and concern about sharing personal information with the robot, indicating limited awareness of the privacy risks involved in such disclosures.

Large Language Models (LLMs) allow social robots to engage in unconstrained open-domain dialogue, but often make mistakes when employed in real-world interactions, requiring adaptation of LLMs to specific conversational contexts. However, LLM adaptation techniques require a feedback signal, ideally for multiple alternative utterances. At the same time, human-robot dialogue data is scarce and research often relies on external annotators. A tool for automatic prediction of user enjoyment in human-robot dialogue is therefore needed. We investigate the possibility of predicting user enjoyment turn-by-turn using an LLM, giving it a proposed robot utterance within the dialogue context, but without access to user response. We compare this performance to the system's enjoyment ratings when user responses are available and to assessments by expert human annotators, in addition to self-reported user perceptions. We evaluate the proposed LLM predictor in a human-robot interaction (HRI) dataset with conversation transcripts of 25 older adults' 7-minute dialogues with a companion robot. Our results show that an LLM is capable of predicting user enjoyment, without loss of performance despite the lack of user response and even achieving performance similar to that of human expert annotators. Furthermore, results show that the system surpasses expert annotators in its correlation with the user's self-reported perceptions of the conversation. This work presents a tool to remove the reliance on external annotators for enjoyment evaluation and paves the way toward real-time adaptation in human-robot dialogue.

Turn-taking is a fundamental aspect of conversation, but current Human-Robot Interaction (HRI) systems often rely on simplistic, silence-based models, leading to unnatural pauses and interruptions. This paper investigates, for the first time, the application of general turn-taking models, specifically TurnGPT and Voice Activity Projection (VAP), to improve conversational dynamics in HRI. These models are trained on human-human dialogue data using self-supervised learning objectives, without requiring domain-specific fine-tuning. We propose methods for using these models in tandem to predict when a robot should begin preparing responses, take turns, and handle potential interruptions. We evaluated the proposed system in a within-subject study against a traditional baseline system, using the Furhat robot with 39 adults in a conversational setting, in combination with a large language model for autonomous response generation. The results show that participants significantly prefer the proposed system, and it significantly reduces response delays and interruptions.

User enjoyment is central to developing conversational AI systems that can recover from failures and maintain interest over time. However, existing approaches often struggle to detect subtle cues that reflect user experience. Large Language Models (LLMs) with reasoning capabilities have outperformed standard models on various other tasks, suggesting potential benefits for enjoyment detection. This study investigates whether models with reasoning capabilities outperform standard models when assessing enjoyment in a human-robot dialogue corpus at both turn and interaction levels. Results indicate that reasoning capabilities have complex, model-dependent effects rather than universal benefits. While performance was nearly identical at the interaction level (0.44 vs 0.43), reasoning models substantially outperformed at the turn level (0.42 vs 0.36). Notably, LLMs correlated better with users’ self-reported enjoyment metrics than human annotators, despite achieving lower accuracy against human consensus ratings. Analysis revealed distinctive error patterns: non-reasoning models showed bias toward positive ratings at the turn level, while both model types exhibited central tendency bias at the interaction level. These findings suggest that reasoning should be applied selectively based on model architecture and assessment context, with assessment granularity significantly influencing relative effectiveness.

Enjoyment is a crucial yet complex indicator of positive user experience in Human-Robot Interaction (HRI). While manual enjoyment annotation is feasible, developing reliable automatic detection methods remains a challenge. This paper investigates a multimodal approach to automatic enjoyment annotation for HRI conversations, leveraging large language models (LLMs), visual, audio, and temporal cues. Our findings demonstrate that both text-only and multimodal LLMs with carefully designed prompts can achieve performance comparable to human annotators in detecting user enjoyment. Furthermore, results reveal a stronger alignment between LLM-based annotations and user self-reports of enjoyment compared to human annotators. While multimodal supervised learning techniques did not improve all of our performance metrics, they could successfully replicate human annotators and highlighted the importance of visual and audio cues in detecting subtle shifts in enjoyment. This research demonstrates the potential of LLMs for real-time enjoyment detection, paving the way for adaptive companion robots that can dynamically enhance user experiences.

While most research in Human-Robot Interaction (HRI) studies one-off or short-term interactions in constrained laboratory settings, a growing body of research focuses on breaking through these boundaries and studying long-term interactions that arise through deployments of robots “in the wild”. Under these conditions, robots need to incrementally learn new concepts or abilities (i.e., “lifelong learning”) to adapt their behaviors within new situations and personalize their interactions with users to maintain their interest and engagement. The second edition of the “Lifelong Learning and Personalization in Long-Term Human-Robot Interaction (LEAP-HRI)” workshop aims to address the developments and challenges in these areas and create a medium for researchers to share their work in progress, present preliminary results, learn from the experience of invited researchers and discuss relevant topics. The workshop focuses on studies on lifelong learning and adaptivity to users, context, environment, and tasks in long-term interactions in a variety of fields such as education, rehabilitation, elderly care, collaborative tasks, service, and companion robots.

User identification is an essential step in creating a personalised long-term interaction with robots. This requires learning the users continuously and incrementally, possibly starting from a state without any known user. In this article, we describe a multi-modal incremental Bayesian network with online learning, which is the first method that can be applied in such scenarios. Face recognition is used as the primary biometric, and it is combined with ancillary information, such as gender, age, height, and time of interaction to improve the recognition. The Multi-modal Long-term User Recognition Dataset is generated to simulate various human-robot interaction (HRI) scenarios and evaluate our approach in comparison to face recognition, soft biometrics, and a state-of-the-art open world recognition method (Extreme Value Machine). The results show that the proposed methods significantly outperform the baselines, with an increase in the identification rate up to 47.9% in open-set and closed-set scenarios, and a significant decrease in long-term recognition performance loss. The proposed models generalise well to new users, provide stability, improve over time, and decrease the bias of face recognition. The models were applied in HRI studies for user recognition, personalised rehabilitation, and customer-oriented service, which showed that they are suitable for long-term HRI in the real world.

In order to achieve more believable interactions with artificial agents, there is a need to produce dialogue that is not only relevant, but also emotionally appropriate and consistent. This paper presents a comprehensive system that models the emotional state of users and an agent to dynamically adapt dialogue utterance selection. A Partially Observable Markov Decision Process (POMDP) with an online solver is used to model user reactions in real-time. The model decides the emotional content of the next utterance based on the rewards from the users and the agent. The previous approaches are extended through jointly modeling the user and agent emotions, maintaining this model over time with a memory, and enabling interactions with multiple users. A proof of concept user study is used to demonstrate that the system can deliver and maintain distinct agent personalities during multiparty interactions.

This paper presents a longitudinal case study of Robot Assisted Therapy for cardiac rehabilitation. The patient, who is a 60-year old male that suffered a myocardial infarction and received angioplasty surgery, successfully recovered after 35 sessions of rehabilitation with a social robot, lasting 18 weeks. The sessions took place directly at the clinic and relied on an exercise regime which was designed by the clinicians and delivered with the support of a social robot and a sensor suite. The robot monitored the patient's progress, and provided personalised encouragement and feedback. We discuss the recovery of the patient and illustrate how the use of a social robot, its sensory systems and its personalised interaction was instrumental to maintain engagement with the programme and to the patient's recovery. Of note is a critical event that was promptly detected by the robot, which allowed fast intervention measures to be taken by the medical staff for the referral of the patient for further surgery.

For practical reasons, most human-robot interaction (HRI) studies focus on short-term interactions between humans and robots. However, such studies do not capture the difficulty of sustaining engagement and interaction quality across long-term interactions. Many real-world robot applications will require repeated interactions and relationship-building over the long term, and personalization and adaptation to users will be necessary to maintain user engagement and to build rapport and trust between the user and the robot. This full-day workshop brings together perspectives from a variety of research areas, including companion robots, elderly care, and educational robots, in order to provide a forum for sharing and discussing innovations, experiences, works-in-progress, and best practices which address the challenges of personalization in long-term HRI.

An increasing number of human-robot interaction (HRI) studies are now taking place in applied settings with children. These interactions often hinge on verbal interaction to effectively achieve their goals. Great advances have been made in adult speech recognition and it is often assumed that these advances will carry over to the HRI domain and to interactions with children. In this paper, we evaluate a number of automatic speech recognition (ASR) engines under a variety of conditions, inspired by real-world social HRI conditions. Using the data collected we demonstrate that there is still much work to be done in ASR for child speech, with interactions relying solely on this modality still out of reach. However, we also make recommendations for child-robot interaction design in order to maximise the capability that does currently exist.