to begin tentative explorations of a topic, as if one is gently tugging on a thread that forms part of a larger fabric or knot, to see what is discovered as it unravels, as in “We need to pull the string a little on those pilot results before we’ll know where to go next”; suggests an issue of complexity and uncertainty that needs to be handled with delicacy to avoid causing disruption; see also black box, which refers to ideas that are even less amenable to inquiry