Comparison between the observed lithium abundance in dwarf stars in clusters of various ages and predictions from models with fast (dashed) and slow (solid line) rotation with six different treatments of mixing near convective boundaries and the modified stability criterion. Data for IC 2391 and IC 2602 (50 Myr) are from Randich et al. (2001); Pleiades data (125 Myr) are from Randich et al. (2001); data for the Hyades (600 Myr) are from Pace et al. (2012) and Cummings et al. (2017) and for Praesepe (600 Myr) are from Cummings et al. (2017); data for NGC 752 (1.5 Gyr) are from Castro et al. (2016); and M 67 (4 Gyr) are from Pace et al. (2012). Data shown from Cummings et al. (2017) is limited to stars for which a T_eff uncertainty was given.