\begin{table}%t2 %\centering \par \caption{\label{tab_corr}Offsets ($\Delta$) and scatter ($\sigma$) of the differences (raw -- column) between the methods: MA$\chi$ (this work). } \par \begin{tabular}{c| cccc} \hline \hline%\noalign{\smallskip} & ADOP &NGS1 & ANNSR & k24\\ & $\Delta / \sigma$ & $\Delta / \sigma$ & $\Delta / \sigma$ & $\Delta / \sigma$\\ \par [Fe/H] & & & & \\ \hline \Max & $-$0.32 / 0.23 & $-$0.41 / 0.29& $-$0.17 / 0.33 & $-$0.34 / 0.26\\ k24 & 0.04 / 0.14& $-$0.07 / 0.25& 0.17 / 0.27&\\ ANNSR& $-$0.13 / 0.22 & $-$0.22 / 0.23 &\\ NGS1 & 0.08 / 0.17& & &\\ \hline \\ ${T_{\rm eff}}$ & & & & \\ \hline \Max & $-$61 / 112 & 80 / 132 & $-$76 / 170 & $-$159 / 160\\ k24 & 98 / 101 & 244 / 166 & 88 / 195& \\ ANNSR & 1 / 114 & 147 / 173 & &\\ NGS1 & $-$142 / 93 & & & \\ \hline \\ $\log g$ & & & \\ \hline \Max &0.51 / 0.39 & 0.38 / 0.43 &0.63 / 0.47 & 0.41 / 0.48\\ k24 & 0.08 / 0.35 & $-$0.02 / 0.42 & 0.26 / 0.48 & \\ ANNSR & $-$0.14 / 0.36 & $-$0.27 / 0.45 & & \\ NGS1 & 0.09 / 0.23 & &\\\hline \end{tabular} \tablefoot{ADOP \citep{lee08_1}, NGS1 \citep{lee08_1}, ANNSR\protect \citep{re_fiorentin07} and k24 \citep{ap06} for the entire sample of selected SEGUE stars.} \end{table}