In many recommendation applications, items may have limited availability thereby causing conflict among users interested in the same items. Over time, this results in unequal user treatment: few users are recommended the limited items and receive preferential treatment, while the rest is left with sub-optimal recommendations, ultimately leading them to leave. In this paper, we formalize the novel problem of compensating users in multi-session recommendations under limited item availability. Our aim is to generate recommendations that not only optimize accuracy, but also compensate users over time for the loss of accuracy incurred in previous iterations. We design compensation strategies that serve users and items in different orders and accommodate various recommendation adoption models. Our algorithms are integrated into SoCRATe (System for Compensating Recommendations with Availability and Time), a framework that enables us to study loss compensation over time. Our experiments on real data demonstrate that to best compensate users for the incurred loss, traditional recommenders need to be revisited to account for item availability. Our experiments on synthetic data explore different parameters of our solution and show that it is much faster than an optimal (brute-force) compensation strategy, while achieving comparable results.

Recent breakthroughs in Artificial Intelligence (AI) obfuscate the boundaries between digital, physical, and social spaces, a trend expected to continue in the foreseeable future. Traditionally, software engineering has prioritized technical aspects, focusing on functional correctness and reliability while often neglecting broader societal implications. With the rise of software agents enabled by Large Language Models (LLMs) and capable of emulating human intelligence and perception, there is a growing recognition of the need for addressing socio-critical issues. Unlike technical challenges, these issues cannot be resolved through traditional, deterministic approaches due to their subjective nature and dependence on evolving factors such as culture and demographics. This paper dives into this problem and advocates the need for revising existing engineering principles and methodologies. We propose a conceptual framework for quality assurance where AI is not only the driver of socio-critical systems but also a fundamental tool in their engineering process. Such framework encapsulates pre-production and runtime workflows where LLM-based agents, so-called artificial doppelgängers, continuously assess and refine socio-critical systems ensuring their alignment with established societal standards.

Abstract The ever-increasing number of systems based on semantic text analysis is making natural language understanding a fundamental task: embedding-based language models are used for a variety of applications, such as resume parsing or improving web search results. At the same time, despite their popularity and widespread use, concern is rapidly growing due to their display of social bias and lack of transparency. In particular, they exhibit a large amount of gender bias, favouring the consolidation of social stereotypes. Recently, sentence embeddings have been introduced as a novel and powerful technique to represent entire sentences as vectors. We propose a new metric to estimate gender bias in sentence embeddings, named bias score. Our solution leverages semantic importance of words and previous research on bias in word embeddings, and it is able to discern between neutral and biased gender information at sentence level. Experiments on a real-world dataset demonstrate that our novel metric can identify gender stereotyped sentences. Furthermore, we employ bias score to detect and then remove or compensate for the more stereotyped entries in text corpora used to train sentence encoders, improving their degree of fairness. Finally, we prove that models retrained on fairer corpora are less prone to make stereotypical associations compared to their original counterpart, while preserving accuracy in natural language understanding tasks. Additionally, we compare our experiments with traditional methods for reducing bias in embedding-based language models.

Abstract Cloud computing and virtualization solutions allow one to rent the virtual machines (VMs) needed to run applications on a pay‐per‐use basis, but rented VMs do not offer any guarantee on their performance. Cloud platforms are known to be affected by performance variability , but a better understanding is still required. This article moves in that direction and presents an in‐depth, multi‐faceted study on the performance variability of VMs. Unlike previous studies, our assessment covers a wide range of factors: 16 VM types from 4 well‐known cloud providers, 10 benchmarks, and 28 different metrics. We present four new contributions. First, we introduce a new benchmark suite ( VMBS ) that let researchers and practitioners systematically collect a diverse set of performance data. Second, we present a new indicator, called V I , that allows for measuring variability in the performance of VMs. Third, we illustrate an analysis of the collected data across four different dimensions: resources , isolation , time , and cost . Fourth, we present multiple predictive models based on machine learning (ML) that aim to forecast future performance and detect time patterns. Our experiments provide important insights on the resource variability of VMs, highlighting differences and similarities between various cloud providers. To the best of our knowledge, this is the widest analysis ever conducted on the topic.

We demonstrate SoCRATe, an online system dedicated to providing adaptive recommendations to users when items have limited availability. SoCRATe is relevant to several real-world applications, among which movie and task recommendations. SoCRATe has several appealing features: (i) watching users as they consume recommendations and accounting for user feedback in refining recommendations in the next round; (ii) implementing loss compensation strategies to make up for sub-optimal recommendations, in terms of accuracy, when items have limited availability; (iii) deciding when to re-generate recommendations on a need-based fashion. SoCRATe accommodates real users as well as simulated users to enable testing multiple recommendation choice models. To frame evaluation, SoCRATe introduces a new set of measures that capture recommendation accuracy, user satisfaction and item consumption over time. All these features make SoCRATe unique and able to adapt recommendations to user preferences in a resource-limited setting. A video of SoCRATe is available at https://youtu.be/4wlaScc_rUo.