Users often struggle with cloud file-sharing applications. Problems appear to arise not only from interface flaws, but also from misunderstanding the underlying semantics of operations like linking, attaching, downloading, and editing. We argue that these difficulties echo long-standing challenges in understanding concepts in programming languages like aliasing, copying, and mutation.

We begin to examine this connection through a formative user study investigating general users’ understanding of file sharing. Our study casts known misconceptions from the programming-education literature into semantically-similar cloud file-sharing tasks. It also uses tasks that echo two kinds of analyses used in programming-education: tracing and programming. Our findings reveal widespread misunderstandings across several tasks.

We also develop a formal semantics of cloud file-sharing operations, reflecting copying, referencing, and mutating shared content. By explicating the semantics, we aim to provide a formal foundation for improving mental models, educational tools, and automated assistance. This semantics can support applications including trace checking, workflow synthesis, and interactive feedback.