# Multi-task Learning for Influence Estimation and Maximization

## TL;DR

This paper introduces IMINFECTOR, a multi-task neural network approach that learns influence-related embeddings from diffusion cascades, enabling scalable, model-independent influence maximization with improved efficiency and seed set quality.

## Contribution

The paper proposes IMINFECTOR, a novel influence maximization method that leverages learned influencer and susceptible vectors, reformulating the problem as a bipartite graph to improve scalability and performance.

## Key findings

- IMINFECTOR scales effectively on large networks with diffusion cascades.
- It outperforms existing algorithms in efficiency and seed set quality.
- The method retains theoretical guarantees in influence maximization.

## Abstract

We address the problem of influence maximization when the social network is accompanied by diffusion cascades. In prior works, such information is used to compute influence probabilities, which is utilized by stochastic diffusion models in influence maximization. Motivated by the recent criticism on the effectiveness of diffusion models as well as the galloping advancements in influence learning, we propose IMINFECTOR (Influence Maximization with INFluencer vECTORs), a unified approach that uses representations learned from diffusion cascades to perform model-independent influence maximization that scales in real-world datasets. The first part of our methodology is a multi-task neural network that learns embeddings of nodes that initiate cascades (influencer vectors) and embeddings of nodes that participate in them (susceptible vectors). The norm of an influencer vector captures the ability of the node to create lengthy cascades and is used to estimate the expected influence spread and reduce the number of candidate seeds. In addition, the combination of influencer and susceptible vectors form the diffusion probabilities between nodes. These are used to reformulate the network as a bipartite graph and propose a greedy solution to influence maximization that retains the theoretical guarantees.We a pply our method in three sizable networks with diffusion cascades and evaluate it using cascades from future time steps. IMINFECTOR is able to scale in all of them and outperforms various competitive algorithms and metrics from the diverse landscape of influence maximization in terms of efficiency and seed set quality.