The article is dealing with the theory and practice in projecting learning tasks. It draws on the analysis of contemporary theories of learning tasks and their relation to projecting of high-quality learning task sets. It defines the contents, the span and the degree in mastering the curriculum in the learning tasks, as well as the ways of creating the forms of tasks according to selected parameters and criteria. In the end, results of practical applications in projecting learning tasks in the discipline of chemistry didactics and the ways of their validation in practice are introduced.