reconcile
Reconciling Predictive Multiplicity in Practice
Behzad, Tina, Casacuberta, Sílvia, Diana, Emily Ruth, Tolbert, Alexander Williams
Many machine learning applications predict individual probabilities, such as the likelihood that a person develops a particular illness. Since these probabilities are unknown, a key question is how to address situations in which different models trained on the same dataset produce varying predictions for certain individuals. This issue is exemplified by the model multiplicity (MM) phenomenon, where a set of comparable models yield inconsistent predictions. Roth, Tolbert, and Weinstein recently introduced a reconciliation procedure, the Reconcile algorithm, to address this problem. Given two disagreeing models, the algorithm leverages their disagreement to falsify and improve at least one of the models. In this paper, we empirically analyze the Reconcile algorithm using five widely-used fairness datasets: COMPAS, Communities and Crime, Adult, Statlog (German Credit Data), and the ACS Dataset. We examine how Reconcile fits within the model multiplicity literature and compare it to existing MM solutions, demonstrating its effectiveness. We also discuss potential improvements to the Reconcile algorithm theoretically and practically. Finally, we extend the Reconcile algorithm to the setting of causal inference, given that different competing estimators can again disagree on specific causal average treatment effect (CATE) values. We present the first extension of the Reconcile algorithm in causal inference, analyze its theoretical properties, and conduct empirical tests. Our results confirm the practical effectiveness of Reconcile and its applicability across various domains.
Reconciling Model Multiplicity for Downstream Decision Making
Du, Ally Yalei, Ngo, Dung Daniel, Wu, Zhiwei Steven
We consider the problem of model multiplicity in downstream decision-making, a setting where two predictive models of equivalent accuracy cannot agree on the best-response action for a downstream loss function. We show that even when the two predictive models approximately agree on their individual predictions almost everywhere, it is still possible for their induced best-response actions to differ on a substantial portion of the population. We address this issue by proposing a framework that calibrates the predictive models with regard to both the downstream decision-making problem and the individual probability prediction. Specifically, leveraging tools from multi-calibration, we provide an algorithm that, at each time-step, first reconciles the differences in individual probability prediction, then calibrates the updated models such that they are indistinguishable from the true probability distribution to the decision-maker. We extend our results to the setting where one does not have direct access to the true probability distribution and instead relies on a set of i.i.d data to be the empirical distribution. Finally, we provide a set of experiments to empirically evaluate our methods: compared to existing work, our proposed algorithm creates a pair of predictive models with both improved downstream decision-making losses and agrees on their best-response actions almost everywhere.
On Model Reconciliation: How to Reconcile When Robot Does not Know Human's Model?
The Model Reconciliation Problem (MRP) was introduced to address issues in explainable AI planning. A solution to a MRP is an explanation for the differences between the models of the human and the planning agent (robot). Most approaches to solving MRPs assume that the robot, who needs to provide explanations, knows the human model. This assumption is not always realistic in several situations (e.g., the human might decide to update her model and the robot is unaware of the updates). In this paper, we propose a dialog-based approach for computing explanations of MRPs under the assumptions that (i) the robot does not know the human model; (ii) the human and the robot share the set of predicates of the planning domain and their exchanges are about action descriptions and fluents' values; (iii) communication between the parties is perfect; and (iv) the parties are truthful. A solution of a MRP is computed through a dialog, defined as a sequence of rounds of exchanges, between the robot and the human. In each round, the robot sends a potential explanation, called proposal, to the human who replies with her evaluation of the proposal, called response. We develop algorithms for computing proposals by the robot and responses by the human and implement these algorithms in a system that combines imperative means with answer set programming using the multi-shot feature of clingo.
Artificial Intelligence Will Not Replace Auditors - Yet - Yellowbook-CPE.com
Artificial Intelligence is a term being used by some to spread the message that machines are going to replace the human workforce, including auditors. This is true--to an extent. AI has so many layers, definitions, and applications that AI can be confusing to understand. At its core, a simple definition is that AI is human intelligence demonstrated by machines. The difficulty in understanding AI and its potential applications for auditors lies in precisely defining'intelligence.' AI is a technology the audit world should more easily understand by replacing'intelligence' with one of its synonyms – 'judgement.'
Parallel Computation of Graph Embeddings
Duong, Chi Thang, Yin, Hongzhi, Hoang, Thanh Dat, Ba, Truong Giang Le, Weidlich, Matthias, Nguyen, Quoc Viet Hung, Aberer, Karl
Chi Thang Duong 1 Hongzhi Yin 2 Thanh Dat Hoang 3 Truong Giang Le Ba 3 Matthias Weidlich 4 Quoc Viet Hung Nguyen 5 Karl Aberer 1 1 EPFL 2 The University of Queensland 3 HUST 5 Griffith University 4 Humboldt-Universit at zu Berlin Abstract Graph embedding aims at learning a vector-based representation of vertices that incorporates the structure of the graph. This representation then enables inference of graph properties. Existing graph embedding techniques, however, do not scale well to large graphs. We therefore propose a framework for parallel computation of a graph embedding using a cluster of compute nodes with resource constraints. We show how to distribute any existing embedding technique by first splitting a graph for any given set of constrained compute nodes and then reconciling the embedding spaces derived for these sub-graphs. We also propose a new way to evaluate the quality of graph embeddings that is independent of a specific inference task. Based thereon, we give a formal bound on the difference between the embeddings derived by centralised and parallel computation. Experimental results illustrate that our approach for parallel computation scales well, while largely maintaining the embedding quality. 1 Introduction Graphs are a natural representation of relations between entities in complex systems, such as social networks or information networks. To enable inference on graphs, a graph embedding may be learned.
A Self-supervised Approach to Hierarchical Forecasting with Applications to Groupwise Synthetic Controls
Mishchenko, Konstantin, Montgomery, Mallory, Vaggi, Federico
When forecasting time series with a hierarchical structure, the existing state of the art is to forecast each time series independently, and, in a post-treatment step, to reconcile the time series in a way that respects the hierarchy (Hyndman et al., 2011; Wickramasuriya et al., 2018). We propose a new loss function that can be incorporated into any maximum likelihood objective with hierarchical data, resulting in reconciled estimates with confidence intervals that correctly account for additional uncertainty due to imperfect reconciliation. We evaluate our method using a non-linear model and synthetic data on a counterfactual forecasting problem, where we have access to the ground truth and contemporaneous covariates, and show that we largely improve over the existing state-of-the-art method.
The future of market research is not what it used to be
People respond differently to automated beings. Take my group of friends, for instance... The other day, while browsing online, I came across this clip of a robotic dog. When I shared it with the room, not everyone responded in the same way. Some felt sorry for Spot and sprang to its defence during the kicking episode, some thought it verged on creepy, while others were sceptical of its practical uses.