This article discusses an ongoing study into issues relevant to the design of learning objects for educational applications via portable digital assistant (PDA) technology. The specific areas of inquiry in this study are: the kinds of learning objects that are effective for PDA delivery; contexts for their effective educational applications; and learning object designs that overcome the limitations of the small display area characteristic of this kind of technology. Initial qualitative data was collected through interviews with respondents who had previously used this technology in teaching and learning. This preliminary data suggests that a learning object effective for PDA delivery should be designed as a resource that supports student-centered learning activities, such as inquiries and problem solving. In particular, two types of learning objects appear to emerge as appropriate for PDA delivery: information objects and conceptual models. The preliminary data of this ongoing study also suggests some interesting ideas regarding more effective design of learning objects for delivery via PDA technology. (Contains 1 table and 1 figure.)