This chapter discusses different types of evidence that conversation analysts use to ground their claims about social action. We begin by reviewing the epistemological perspective of CA, which demands that evidence reflect participants’ orientations; as a critical part of understanding the terms ‘participant orientation’ and ‘relevance,’ here we also discuss two ways in which CA’s position and emphasis on them are commonly misunderstood. The bulk of this chapter then reviews and illustrates a range of types of participant-orientation evidence. We organize our presentation of types of evidence roughly by sequential position vis-à-vis the focal action about which the analyst is making claims, including evidence to be found in: (i) next-turn, (ii) same-turn (e.g., same-TCU self-repair, accounts), (iii) prior turn or sequence, (iv) third turn/position (e.g., repair after next turn, courses of action/activity), (v) fourth turn/position, and (vi) more distal positions. We also discuss other forms of evidence that are not necessarily defined by sequential position, including: (i) third-party conduct, (ii) reported conduct, (iii) deviant cases, and (iv) distributional evidence. We conclude by offering some brief reflections on bringing different types and positions of evidence together toward the construction of an argument.