Carotene: A Job Title Classification System for the Online Recruitment Domain

In the online job recruitment domain, accurate classification of jobs and resumes to occupation categories is important for matching job seekers with relevant jobs. An example of such a job title classification system is an automatic text document classification system that utilizes machine learning. Machine learning-based document classification techniques for images, text and related entities have been well researched in academia and have also been successfully applied in many industrial settings. In this paper we present Carotene, a machine learning-based semi-supervised job title classification system that is currently in production at CareerBuilder. Carotene leverages a varied collection of classification and clustering tools and techniques to tackle the challenges of designing a scalable classification system for a large taxonomy of job categories. It encompasses these techniques in a cascade classifier architecture. We first present the architecture of Carotene, which consists of a two-stage coarse and fine level classifier cascade. We compare Carotene to an early version that was based on a flat classifier architecture and also compare and contrast Carotene with a third party occupation classification system. The paper concludes by presenting experimental results on real world industrial data using both machine learning metrics and actual user experience surveys.