Synchronizing Rankings via Interactive Communication

TL;DR

This paper develops order-optimal protocols for synchronizing two remote rankings through interactive communication, accounting for various editing operations and communication constraints.

Contribution

It introduces a novel model for ranking synchronization with different communication constraints and provides order-optimal protocols for various editing operations.

Findings

Protocols are order-optimal compared to lower bounds.

Effective handling of deletions, insertions, and transpositions.

Applicable to ranking systems like playlists and recommender systems.

Abstract

We consider the problem of exact synchronization of two rankings at remote locations connected by a two-way channel. Such synchronization problems arise when items in the data are distinguishable, as is the case for playlists, tasklists, crowdvotes and recommender systems rankings. Our model accounts for different constraints on the communication throughput of the forward and feedback links, resulting in different anchoring, syndrome and checksum computation strategies. Information editing is assumed of the form of deletions, insertions, block deletions/insertions, translocations and transpositions. The protocols developed under the given model are order-optimal with respect to genie aided lower bounds.