There has been growing interest in both developing and implementing service robots for health care and home environments. In addition to a variety of functions supported by robotic technology, the interaction between a human and robot, including human emotional experiences, can affect perceived service quality and satisfaction. Based on a survey of existing service robot applications and associated interface requirements, we consider anthropomorphism as a critical characteristic of the robot interface. We propose a preliminary research framework to support identification of the exact relationship between robot interface features and user (emotional) responses in service contexts. Future experimental investigations based on the framework are to be conducted.