This document discusses human-computer interaction (HCI) research in user-centered design (UCD). It begins with definitions of key terms like UX, HCI, and UCD. It emphasizes the importance of UCD in improving software success rates and reducing costs from poor requirements gathering. The document then provides examples of HCI research areas like the technology acceptance model for predicting product usage and recent approaches using neuroscience. It concludes by encouraging the adoption of UCD principles and referring to knowledgeable resources in the HCI field.