The best method for determining the size of learning objects (LOs) so as to optimise their reusability has been a topic of debate for years now. Although there appears to be agreement on basic assumptions, developed guidelines and principles are often in conflict. This study shows that this confusion stems from the fact that in the literature, hardly any attention is paid to different types of reusability. This study not only shows that there are different types of reusability, but also that different types of reusability go together with different principles for developing LOs and for determining LO size. A grounded theory analysis was performed on separate statements on LO development in 71 selected publications from LO literature. This resulted in the development of four scenarios for LO development, each with their own definition of reusability and their own principle for determining the size of LOs. A field test with 11 experts showed that the scenarios are recognisable. In higher education, educational technologists often assist amateur LO developers. Educational technologists can use the scenarios to determine which definition of reusability is applicable to their situation and which principle for determining the size of LOs should be applied. (Contains 2 tables and 1 figure.)