  Autocompletion is an approach that extends and continues partial user input.
We propose to interpret autocompletion as a basic interaction concept in
human-AI interaction. We first describe the concept of autocompletion and
dissect its user interface and interaction elements, using the well-established
textual autocompletion in search engines as an example. We then highlight how
these elements reoccur in other application domains, such as code completion,
GUI sketching, and layouting. This comparison and transfer highlights an
inherent role of such intelligent systems to extend and complete user input, in
particular useful for designing interactions with and for generative AI. We
reflect on and discuss our conceptual analysis of autocompletion to provide
inspiration and a conceptual lens on current challenges in designing for
human-AI interaction.
