One for All: Simultaneous Metric and Preference Learning over Multiple Users
This work addresses preference modeling for crowds, offering a method that balances individual flexibility with amortized learning costs, but it is incremental as it builds on existing metric and preference learning frameworks.
The paper tackles the problem of jointly learning a shared distance metric and individual user preferences from paired comparisons, showing that sample complexity improves when the metric is low-rank and providing recovery guarantees under certain assumptions.
This paper investigates simultaneous preference and metric learning from a crowd of respondents. A set of items represented by $d$-dimensional feature vectors and paired comparisons of the form ``item $i$ is preferable to item $j$'' made by each user is given. Our model jointly learns a distance metric that characterizes the crowd's general measure of item similarities along with a latent ideal point for each user reflecting their individual preferences. This model has the flexibility to capture individual preferences, while enjoying a metric learning sample cost that is amortized over the crowd. We first study this problem in a noiseless, continuous response setting (i.e., responses equal to differences of item distances) to understand the fundamental limits of learning. Next, we establish prediction error guarantees for noisy, binary measurements such as may be collected from human respondents, and show how the sample complexity improves when the underlying metric is low-rank. Finally, we establish recovery guarantees under assumptions on the response distribution. We demonstrate the performance of our model on both simulated data and on a dataset of color preference judgements across a large number of users.