Traditional usability methods are of limited use when evaluating systems designed for distant, diverse populations. In this paper, we describe a study conducted in two Ghanaian villages that evaluated an audio computer designed for people living in oral cultures. Informed by ICTD and orality-grounded HCID, we modified existing usability testing practices and we reflect on the utility of these adaptations. We found that conducting a culturally appropriate study often meant forgoing more traditional approaches in favor of flexible, opportunistic methods. We acknowledge the challenges of adapting traditional usability methods for oral, rural users. However, we found that by implementing strategic modifications led by local staff, our study produced valuable, actionable results.