\begin{figure}[!t]
\centering
{\scriptsize  
\begin{tabular}{l|r|l|l}  
& \textbf{Dataset} & Used by us & Used by others \\\hline 
 & telecom & \cite{keung08a} & \cite{shepperd97}\\
 &   kemerer & \cite{keung08a} & \cite{shepperd97,Finnie1997}  \\
 &  cocomo81o &\cite{Menzies2006,Lum2008,Kocaguneli2010} &\\
 &  desharnaisL1 & \cite{Kocaguneli2010} &\\ 
 weaker&   cocomo81s &\cite{Menzies2006,Lum2008,Kocaguneli2010} &\\ 
 data& desharnaisL3 & \cite{Kocaguneli2010}  &\\
 sets &  albrecht & \cite{keung08a}, &\cite{Li2009,Li2009a,shepperd97,shepperd96,Finnie1997} \\ 
 &  cocomo81e & \cite{Menzies2006,Bakir2009,Kocaguneli2010} &\\ 
 &  nasa93\_center\_5 &\cite{Menzies2006,Lum2008,Kocaguneli2010} &\\ 
 & desharnaisL2 & \cite{Kocaguneli2010}   &\\\hline 
 & desharnais & \cite{keung08b,keung08a,keung2008b,Kocaguneli2010} & \cite{shepperd97,Li2008,Kadoda2000,Kirsopp2002,Li2009,Li2009a}\\ 
 & maxwell & &\cite{Li2009a,Sentas2005} \\
 & sdr &  &\cite{Kultur2008,Turhan2007} \\ 
 &  nasa93\_center\_1 & \cite{Menzies2006,Lum2008,Kocaguneli2010}  &\\
 stronger& miyazaki94 & &\cite{Miyazaki1994} \\
 data& nasa93\_center\_2 &\cite{Menzies2006,Lum2008,Kocaguneli2010} &\\ 
 sets & finnish &&\cite{Briand1999,shepperd97} \\
 & cocomo81 &\cite{Menzies2006,Lum2008,Kocaguneli2010} &\cite{Boehm1981}, \\
 & nasa93 &\cite{Menzies2006,Lum2008,Kocaguneli2010} &\\ 
 & china & this study&\\
\end{tabular}}
\caption{A sample of effort estimation papers that use the
data sets explored in this paper. The rows of this table are sorted according to \fig{error_datasets}.
The top/bottom rows show data sets that are {\em weakest}/{\em strongest}
at distinguishing different algorithms.
The horizontal line divides the data according the 15\% rule, proposed in the text.
}\label{fig:dataranks}
\end{figure}