Dr. Julian Decius has published an overview article on informal workplace learning in the Psychologische Rundschau. It defines what informal learning actually is, how it can be distinguished from related forms of learning and how it can be measured. It also provides an overview of the predictors and consequences of informal learning based on the conceptual model by Scott Tannenbaum and Mikhail Wolfson (2022) and sets out a research agenda.
The article is originally published in German, but an English version is included in the online supplementary material and is accessible here.