Comparison between our model predictions and observational data (filled circles) for surface lithium abundance, for the selected sample of young open clusters, namely (from the top left panel), Ic2602, α Per, Blanco 1, Pleiades, and NGC 2516. In each panel we show both the low-convection efficiency (α_PMS = 1.0, red-filled squares and dotted line) and the high-convection efficiency models (α_PMS = α_MS, dashed line and small black-filled squares). We also plotted the mass and the corresponding theoretical uncertainties on both the effective temperature and lithium abundance, for low- and high-convection efficiency models.