Comparison of [Fe/H], [Al/H], [Ca/H], and [Ti/H] abundance ratios derived from H-band and K-band spectral regions. The symbols are the same as in Fig. 3, and the typical measurement error is plotted in the upper left corner of each panel. The abundance ratios derived from the K band are generally higher than those from the H band. These discrepancies are particularly significant for Al, Ca, and Ti elements.