Case Study: Applying Decision Focused Learning in the Real World

Aditya Mayte
Kai Wang
Shresth Verma
NeurIPS Workshop on Trustworthy and Socially Responsible Machine Learning (2022) (to appear)

Abstract

Many real world optimization problems with underlying unknown model parameters are solved using the predict-then-optimize framework. In particular, a model
is learnt to first predict the parameters of the optimization problem, which is
subsequently solved using an optimization algorithm. However, this approach
maximises for the predictive accuracy rather than the quality of the final solution.
Decision Focused Learning (DFL) solves this objective mismatch by integrating
the optimization problem in the learning pipeline. Previous works have only shown
the applicability of DFL in simulation settings. In our work, we consider the
optimization problem of scheduling limited live service calls in Maternal and Child
Health Awareness Programs and model it using Restless Multi-Armed Bandits
(RMAB). In collaboration with an NGO, we conduct a large-scale field study
consisting of 9000 beneficiaries for 6 weeks and track key engagement metrics
in a mobile health awareness program. To the best of our knowledge this is the
first real world study involving Decision Focused Learning. We demonstrate that
beneficiaries in the DFL group experience statistically significant reductions in
cumulative engagement drop, while those in the Predict-then-Optimize group do
not. This establishes the practicality of use of decision focused learning for real
world problems. We also demonstrate that DFL learns a better decision boundary
between the RMAB actions, and strategically predicts parameters which contribute
most to the final decision outcome.

Research Areas