Prior to SCORM 2004 4th Edition, the SCORM Run-Time Environment Data
Model defined elements that were tracked and accessed purely on a learner
attempt per SCO basis. Using this model, SCOs could not set or retrieve
information from other SCOs or even other attempts on the same SCO.
While this methodology promoted interoperability, it prevented several
instructional approaches and in some cases forced the creation of larger,
less re-usable, SCOs.