252 ◾ Software Designers in Action: A Human-Centric Look at Design Work
© 2010 Taylor & Francis Group, LLC
busy lane to get into a turning lane on the le side. An1’s response, “I hate to bog down
in that detail,” treats as problematic such details of trac conditions, and is a remark that
garners immediate assent, without delay, from An2. An1 proceeds to construct a turn that,
in the interests of keeping “it moving,” proposes, “what simplifying assumptions could
we make initially,” to obviate the issue. In this case, as in the rst, an assumption marks a
contrast with the world, that is, An2’s “real scenario” (Line 4). But an importantly dier-
ent action is being performed with the idea. An1’s simplifying assumption is employed as