Missing Controls on Quick Selection Tool

According to the documentation, the Quick Selection Tool has several controls I can use to fine tune its performance, but on my screen, they're not there. Supposedly, they're on the bar across the top of my screen, where i find all the controls for the other tools (which I use successfully) but they aren't there for me. I've tried resetting the tool, but that doesn't help either. Can anybody tell me how to make those controls reappear.  Thanks in advance,