Conversations involving people with communication disorders or other forms of communicative impairment, such as those with dementia, autism, aphasia, or hearing impairment, differ in systematic ways from typical conversations (i.e., those involving participants without significant communicative or cognitive challenges). Drawing from CA work over the last few decades, this chapter discusses methodological issues involved in data collection in this field and in the transcription and analysis of these types of data. Analysis of the ways in which these interactions are distinctive and ‘atypical’ as regards social actions and the practices used in their construction and deployment involves a form of comparative analysis drawing on CA findings concerning typical interaction. The chapter also discusses other, more explicit, forms of comparative analysis regularly undertaken in this field, including comparison of participants’ conversations over time, and the comparison of how conversations involving participants with one type of communicative impairment compare with those of participants with a different form of impairment. One way in which the latter type of investigation can be developed is discussed in relation to a certain interactional feature – here, interruptive, other-initiation of repair – and how it may be traced across conversations involving participants with different communicative impairments.