Tzur and Simon (2004) postulated two stages of concept development, participatory and anticipatory. The distinction between the two stages was exemplified by what they termed "the next-day phenomenon" in which learners who could solve a task one day in the context of the activity through which they made the abstraction, could not solve what seemed to be the same task in a subsequent lesson when the students were not engaged in or thinking about the activity. Here we expand the application of this theoretical distinction by providing two examples of use of the distinction in analyses of data segments that are different from the next-day phenomenon. [For the complete proceedings, see ED597799.]