arXiv subjects

Ville Satopää

Publications and source records attributed to Ville Satopää.

4 recordsLinked to original sources

arXiv2026

Beyond AI advice -- independent aggregation boosts human-AI accuracy

Artificial intelligence (AI) is broadly deployed as an advisor to human decision-makers: AI recommends a decision and a human accepts or rejects the advice. This approach, however, has several limitations: People frequently ignore accurate advice and rely too much on inaccurate advice, and their decision-making skills may deteriorate over time. Here, we compare the AI-as-advisor approach to the hybrid confirmation tree (HCT), an alternative strategy that preserves the independence of human and AI judgments. The HCT elicits a human judgment and an AI judgment independently of each other. If they agree, that decision is accepted. If not, a second human breaks the tie. For the comparison, we used 10 datasets from various domains, including medical diagnostics and misinformation discernment, and a subset of four datasets in which AI also explained its decision. The HCT outperformed the AI-as-advisor approach in all datasets. The HCT also performed better in almost all cases in which AI offered an explanation of its judgment. Using signal detection theory to interpret these results, we find that the HCT outperforms the AI-as-advisor approach because people cannot discriminate well enough between correct and incorrect AI advice. Overall, the HCT is a robust, accurate, and transparent alternative to the AI-as-advisor approach, offering a simple mechanism to tap into the wisdom of hybrid crowds.

cs.HC↗

arXiv2026

The hybrid confirmation tree: A robust strategy for hybrid intelligence

Combining human and artificial intelligence (AI) is a potentially powerful approach to boost decision accuracy. However, few such approaches exist that effectively integrate both types of intelligence while maintaining human agency. Here, we introduce and evaluate the hybrid confirmation tree, a simple aggregation strategy that compares the independent decisions of both a human and AI, with disagreements triggering a second human tiebreaker. Through analytical derivations, we show that the hybrid confirmation tree can match and exceed the accuracy of a three-person human majority vote while requiring fewer human inputs, particularly when AI accuracy is comparable to or exceeds human accuracy. We analytically demonstrate that the hybrid confirmation tree's ability to achieve complementarity -- outperforming individual humans, AI, and the majority vote -- is maximized when human and AI accuracies are similar and their decisions are not overly correlated. Empirical reanalysis of six real-world datasets (covering skin cancer diagnosis, deepfake detection, geopolitical forecasting, and criminal rearrest) validates these findings, showing that the hybrid confirmation tree improves accuracy over the majority vote by up to 10 percentage points while reducing the cost of decision making by 28--44$\%$. Furthermore, the hybrid confirmation tree provides greater flexibility in navigating true and false positive trade-offs compared to fixed human-only heuristics like hierarchies and polyarchies. The hybrid confirmation tree emerges as a practical, efficient, and robust strategy for hybrid collective intelligence that maintains human agency.

cs.HC↗

arXiv2015

Combining and Extremizing Real-Valued Forecasts

The weighted average is by far the most popular approach to combining multiple forecasts of some future outcome. This paper shows that both for probability or real-valued forecasts, a non-trivial weighted average of different forecasts is always sub-optimal. More specifically, it is not consistent with any set of information about the future outcome even if the individual forecasts are. Furthermore, weighted averaging does not behave as if it collects information from the forecasters and hence needs to be extremized, that is, systematically transformed away from the marginal mean. This paper proposes a linear extremization technique for improving the weighted average of real-valued forecasts. The resulting more extreme version of the weighted average exhibits many properties of optimal aggregation. Both this and the sub-optimality of the weighted average are illustrated with simple examples involving synthetic and real-world data.

stat.ME↗

arXiv2015

Combining Probability Forecasts and Understanding Probability Extremizing through Information Diversity

Randomness in scientific estimation is generally assumed to arise from unmeasured or uncontrolled factors. However, when combining subjective probability estimates, heterogeneity stemming from people's cognitive or information diversity is often more important than measurement noise. This paper presents a novel framework that uses partially overlapping information sources. A specific model is proposed within that framework and applied to the task of aggregating the probabilities given by a group of forecasters who predict whether an event will occur or not. Our model describes the distribution of information across forecasters in terms of easily interpretable parameters and shows how the optimal amount of extremizing of the average probability forecast (shifting it closer to its nearest extreme) varies as a function of the forecasters' information overlap. Our model thus gives a more principled understanding of the historically ad hoc practice of extremizing average forecasts.

stat.ME↗