Machine Learning models are prevalent in critical human-related decision making, such as resume filtering and loan applications. Refused individuals naturally ask what could change the decision, should they reapply. This question is hard for the model owner to answer: first, the model is typically complex and not easily interpretable; second, models may be updated periodically; and last, attributes of the individual seeking approval are apt to change in time. While each of these challenges have been extensively studied in isolation, their conjunction has not. To this end, we propose a novel framework that allows users to devise a plan of action to individuals in presence of Machine Learning classification, where both the ML model and the user properties are expected to change over time. Our technical solution is currently confined to a particular yet important class of models, namely those of tree-based ensembles (Random Forests, Gradient Boosted trees). In this setting it uniquely combines state-of-the-art solutions for single model interpretation, domain adaptation techniques for predicting future models, and constraint databases to represent and query the space of possible actions. We devise efficient algorithms that leverage these foundations in a novel solution, and experimentally show that they are effective in proposing useful and actionable steps leading to the desired classification.

The interpretability of complex Machine Learning models is coming to be a critical social concern, as they are increasingly used in human-related decision-making processes such as resume filtering or loan applications. Individuals receiving an undesired classification are likely to call for an explanation - preferably one that specifies what they should do in order to alter that decision when they reapply in the future. Existing work focuses on a single ML model and a single point in time, whereas in practice, both models and data evolve over time: an explanation for an application rejection in 2018 may be irrelevant in 2019 since in the meantime both the model and the applicant's data can change. To this end, we propose a novel framework that provides users with insights and plans for changing their classification in particular future time points. The solution is based on combining state-of-the-art algorithms for (single) model explanations, ones for predicting future models, and database-style querying of the obtained explanations. We propose to demonstrate the usefulness of our solution in the context of loan applications, and interactively engage the audience in computing and viewing suggestions tailored for applicants based on their unique characteristic.