1 Introduction  
2 A warm-up: single-crowd stopping rules  
3 Omniscient benchmarks for crowd selection  
4 Crowd selection against the deterministic benchmark  
5 The randomized benchmark  
6 Crowd selection against the randomized benchmark  
7 The bi-criteria objective  
8 Experimental results: single crowd  
9 Experimental results: crowd-selection algorithms  
10 Related work  
11 Open questions