 Hans Kamp (1981), the founder of contextualism, maintained that the extension of vague words orbits the speaker’s store of conversational commitments. He notes that the commitment pressures the speaker to adjust past judgments to current judgments. This backward smoothing undermines the search for a sharp transition. The diagnostic potential of this smoothing is first recognized by Diana Raffman (1994). Switching categories (e.g., from blue to green) between two neighboring, highly similar items in a sorites series, without installing a boundary, is enabled by a gestalt switch that occurs between the two judgments. Switching categories comes at a cost, however; so once the classifier has switched to a new category, she will stay in the new category as long as she can. In particular, if she now reverses direction and goes back down the series, she will continue to classify as green some items she previously classified as blue. This pattern of judgments, hysteresis, has the effect of smoothing out the category shift so that the seeming continuity of the series is preserved. Instead of merely inviting psychologists to verify her predictions about hysteresis effects in sorites series, Raffman (2014, 146–156) collaborates with two psychologists to run an experiment that confirms them. 