Chao Zhang

The habit-intention interaction effect tested in behavior prediction studies is a prominent example of statistical moderation analysis in health psychology. Motivated by the mixed empirical findings concerning the effect and long-standing criticisms on estimating and interpreting interaction effects, I used a computational modeling approach to evaluate whether the habit-intention interaction effect estimated from statistical analysis is adequate for inferring the underlying cognitive mechanism assumed by contemporary habit theories. By manipulating the presence or absence of a habit-moderating mechanism in the data-generating model, statistical analyses were performed on the simulated data to examine the correspondence of the estimated interaction effect to the manipulation. Results suggest that while the conventional statistical approach can be indicative of the underlying mechanism, the direction and size of the estimated effect are often misleading in relation to the substantive theory. I identified the cause of the problem from a causal perspective (i.e., intention as a common cause of habit strength and behavior) and discussed potential remedies.

Social robots are increasingly applied as health behavior change interventions, yet actionable knowledge to guide their design and evaluation remains limited. This systematic review synthesizes (1) the behavior change strategies used in existing HRI studies employing social robots to promote health behavior change, and (2) the evaluation methods applied to assess behavior change outcomes. Relevant literature was identified through systematic database searches and hand searches. Analysis of 39 studies revealed four overarching categories of behavior change strategies: coaching strategies, counseling strategies, social influence strategies, and persuasion-enhancing strategies. These strategies highlight the unique affordances of social robots as behavior change interventions and offer valuable design heuristics. The review also identified key characteristics of current evaluation practices, including study designs, settings, durations, and outcome measures, on the basis of which we propose several directions for future HRI research.

As machine learning models become increasingly prevalent in time series applications, Explainable Artificial Intelligence (XAI) methods are essential for understanding their predictions. Within XAI, feature attribution methods aim to identify which input features contribute the most to a model’s prediction, with their evaluation typically relying on perturbation-based metrics. Through systematic empirical analysis across multiple datasets, model architectures, and perturbation strategies, we reveal previously overlooked class-dependent effects in these metrics: they show varying effectiveness across classes, achieving strong results for some while remaining less sensitive to others. In particular, we find that the most effective perturbation strategies often demonstrate the most pronounced class differences. Our analysis suggests that these effects arise from the learned biases of classifiers, indicating that perturbation-based evaluation may reflect specific model behaviors rather than intrinsic attribution quality. We propose an evaluation framework with a class-aware penalty term to help assess and account for these effects in evaluating feature attributions, offering particular value for class-imbalanced datasets. Although our analysis focuses on time series classification, these class-dependent effects likely extend to other structured data domains where perturbation-based evaluation is common (Code and results are available at https://github.com/gregorbaer/class-perturbation-effects.).

Technical and ethical concerns impede the establishment of trust among healthcare professionals (HCPs) in developing artificial intelligence (AI)-based decision support. Yet, our understanding of trust models is constrained, and a standard accepted approach to evaluating trust in AI models is still lacking. We introduce a novel methodology to assess and quantify HCPs’ perceived trust in an interpretable machine learning model that serves as clinical decision support for diagnosing COVID-19 cases. Our approach leverages fuzzy cognitive maps (FCMs) to elicit and quantify HCPs’ trust mental models for understanding trust dynamics in clinical diagnosis. Our study reveals that HCPs rely predominantly on their own expertise when interacting with the developed interpretable clinical decision support. Although the model’s interpretations offer limited assistance in diagnostic tasks, they facilitate the HCPs’ utilization of it. However, the impact of these interpretations on the establishment of perceived trust varies among HCPs, which can lead to an increase in trust for some while decreasing it for others. To validate quantified perceived trust, we employ the degree of agreement metric, which quantitatively assesses whether HCPs lean more towards their own expertise or rely on the model’s recommendations in diagnostic tasks. We found significant alignment between the conclusions of the two metrics, indicating successful modeling and quantification of perceived trust. Plus, a moderate to strong positive correlation between the two metrics confirmed this conclusion. This means that FCMs can quantify HCPs’ perceived trust, aligning with their actual diagnostic advice shift after interacting with the model.

The increasing use of artificial intelligence (AI) models across various fields has raised concerns about whether these models can meet user trust expectations. As a result, researchers are focusing on assessing AI models’ performance relative to user expectations to determine trust levels. Evidence suggests that effective interaction with eXplainable AI (XAI) techniques can mitigate over-reliance on AI models and better align user expectations with the actual capabilities of these models in decision-making. In this study, we analyze trust from two perspectives: perceived trust, based on user self-reported trust, and demonstrated trust, which evaluates whether users, when given a choice, prefer to rely on AI or make decisions independently. We also explore how different interactions between human subjects and XAI models, along with varying levels of task risk, influence trust. Our findings reveal that these two types of trust are substantially different; human subjects do not always exhibit trust behavior in actual decision-making tasks, even when they perceive themselves as trusting the AI. Furthermore, we show that an AI model’s low error rate in making correct decisions can influence human subjects’ mental models, leading them to report a higher tendency to trust the AI. Finally, we conclude that human perceptions of trust are fragile and may change based on ongoing interactions with the model.

To design social robots to effectively promote health behavior change, it is essential to understand how people respond to various health communication strategies employed by these robots. This study examines the effectiveness of two types of social control strategies from a social robot, relationship-focused strategies (emphasizing relational consequences) and target-focused strategies (emphasizing health consequences), in encouraging people to reduce sedentary behavior. A two-session lab experiment was conducted (n = 135), where participants first played a game with a robot, followed by the robot persuading them to stand up and move using one of the strategies. Half of the participants joined a second session to have a repeated interaction with the robot. Results showed that relationship-focused strategies motivated participants to stay active longer. Repeated sessions did not strengthen participants' relationship with the robot, but those who felt more attached to the robot responded more actively to the target-focused strategies. These findings offer valuable insights for designing persuasive strategies for social robots in health communication contexts.

The surge of Artificial Intelligence (AI) for automatic decision-making raises concerns about transparency and interpretability of AI models. Explainable AI (XAI) addresses this by providing insights into AI predictions. Despite the availability of various methods for explaining decisions based on tabular data, there is no consensus on their effectiveness for different types of users. This paper introduces a novel XAI method, the Visual Map, and presents a human-grounded evaluation study comparing it with three common XAI methods. In an online experiment (N = 49), participants with either high or low AI-literacy evaluated all four methods in terms of explanation satisfaction, cognitive load, and overall evaluation in the same classification task environment. High AI-literacy participants were largely indifferent to the four methods, whereas low AI-literacy participants favoured the visual map, perceiving it as the least cognitively demanding. Our findings contribute to the evaluation and development of XAI methods for different types of end-users.