A little taxonomy of open-endedness

This paper aims to provide a partial taxonomy of the ways that the term open-endedness is used in Artificial Life, the ways that open-endedness is used outside of Artificial Life, open-endedness referred to via other terms. The definitions for open-endedness fall in the conceptual or measuring categories. The conceptual categories are rich, while the measuring categories---and the actual measurements---tend to be simplistic. Related concepts that we describe include meta-learning, compositionality (in language), creativity.