This document summarizes Elka Mao's research portfolio, which includes experience in user research methodologies, field research, and relevant industry exposure. It provides three case studies as examples of her work. The first case study describes segmentation research on mobile payment app users. The second outlines conjoint analysis research to determine optimal features for a video streaming service's VIP membership. The third presents development of a credit scoring model for rural lending in China. Across her portfolio, Elka applies mixed research methods and data analysis skills to provide user insights and solve business problems.