Third wave HCI (Human Computer Interaction) proposes an innovative method for framing human computer interactions by putting emphasis on the terms and conditions of the interactive relationship prior to determinations concerning the human subject and its computational object. As promising as this "relational turn" appears to be, there are important theoretical, epistemological, and axiological challenges that remain and need to be addressed. This chapter takes up and investigates a number of these open questions regarding third wave HCI. It begins by briefly reconsidering the three waves or paradigms of HCI research and demonstrating how what appears last in the numbered sequence, the third wave, is actually older and "more original" than it initially appears to be. It then examines the opportunities and challenges of the phenomenological commitment that is operationalized in third wave HCI. And it concludes by identifying and outlining the consequences of this innovation for current and future research efforts.