A sleep diary is an important tool to gather subjective sleep data, which provides key information for the diagnosis of a variety of sleep disorders. In 2012, an expert panel created a standardized sleep diary in pen-and-paper format. However, pen-and-paper has certain limitations, in particular, it is difficult to monitor participant compliance and memory bias. We improve upon these limitations with a digital design and identify benefits and drawbacks of the pen-and-paper format in comparison to a digital sleep diary in an empirical study based on an action design research project. The main contribution consists of five design guidelines: i) use the native environment, ii) utilize established input methods, iii) embed customization to minimize participant workload, iv) evaluate the application continuously using analytics, and v) integrate digital elements to increase compliance. Furthermore, we propose a mobile application design for a digital sleep diary that is in accordance with these guidelines
