Vocabulary
artifact - Some datum generated explicitly or implicitly by the learner. An example explicit artifact is a a note or drawing. An implicit artifact is how long their web click trail or how long they spent viewing a block of text.
rim - Intuitively, what an artifact passes through to fall in the sock. Each rim defines the shape (type) of the artifact and the context (POt) of its creation. (previously known as artifact definition)
sock - A container for the artifacts that a particular user passed through a particular rim in a a particular run (a sock is specified by the 3-tuple <user,rim,run>). Each entry into the sock contains the artifact, the universal time in which it was deposited, and the exact version of the POt against which it was created (<artifact, artifactTimestamp, specificPOt>