Jacopo Amidei

Youmna Farag, Charlotte O. Brand, Jacopo Amidei et al. · cambridge

Recent research on argumentative dialogues has focused on persuading people to take some action, changing their stance on the topic of discussion, or winning debates. In this work, we focus on argumentative dialogues that aim to open up (rather than change) people's minds to help them become more understanding to views that are unfamiliar or in opposition to their own convictions. To this end, we present a dataset of 183 argumentative dialogues about 3 controversial topics: veganism, Brexit and COVID-19 vaccination. The dialogues were collected using the Wizard of Oz approach, where wizards leverage a knowledge-base of arguments to converse with participants. Open-mindedness is measured before and after engaging in the dialogue using a questionnaire from the psychology literature, and success of the dialogue is measured as the change in the participant's stance towards those who hold opinions different to theirs. We evaluate two dialogue models: a Wikipedia-based and an argument-based model. We show that while both models perform closely in terms of opening up minds, the argument-based model is significantly better on other dialogue properties such as engagement and clarity.

Ishari Amarasinghe, Salvatore Romano, Jacopo Amidei et al.

Estimation of mis/disinformation prevalence in social media is crucial for designing mitigation strategies to limit its impact. Yet, such estimations are subject to several uncertainties that are rarely quantified jointly. In this study, we present a methodological contribution in which confidence intervals were used to quantify uncertainties related to mis/disinformation prevalence. The analysis draws on a multi-platform, multilingual dataset annotated by professional fact-checkers. Data were collected between March and April 2025 from Facebook, Instagram, LinkedIn, TikTok, X/Twitter, and YouTube across four EU Member States (France, Poland, Slovakia, and Spain). We account for different causes of uncertainty: (i) sample uncertainty, (ii) annotation uncertainty arising from human disagreement and misclassification, and (iii) data retrieval uncertainty induced by keyword-based data collection. First, we estimate the uncertainty arising from the different causes separately using confidence intervals, simulation-based methods, and bootstrapping. Finally, we combined multinomial simulations of annotator behaviour with keyword and post-resampling to capture the joint impact of measurement uncertainty on mis/disinformation prevalence estimates. The proposed methodological approach highlights the importance of uncertainty-aware estimation of mis/disinformation prevalence for robust analysis. The empirical results of this study show that keyword-based data retrieval can exceed baseline variability, leading to wider confidence intervals around prevalence estimates.

Jacopo Amidei

Annotation reproducibility and accuracy rely on good consistency within annotators. We propose a novel method for measuring within annotator consistency or annotator Intraobserver Agreement (IA). The proposed approach is based on transitivity, a measure that has been thoroughly studied in the context of rational decision-making. The transitivity measure, in contrast with the commonly used test-retest strategy for annotator IA, is less sensitive to the several types of bias introduced by the test-retest strategy. We present a representation theorem to the effect that relative judgement data that meet transitivity can be mapped to a scale (in terms of measurement theory). We also discuss a further application of transitivity as part of data collection design for addressing the problem of the quadratic complexity of data collection of relative judgements.