All the data used in this study is 
available at \protect\url{http://promisedata.org/data}.
As shown in \fig{data}, our data includes:
\bi
\item
Enhancements made to a U.K. telecommunications product.
\item
Projects collected by Miyazaki et al~\cite{miyazaki94} originally comparing ``robust regression`` to the least squares criteria.
\item
Finnish Information Systems projects collected by the TIEKE organization.
\item
A large dataset of chinese software projects.
\item
Large COBOL business projects collected by Kemerer et al~\cite{kemerer87}.
\item
And the standard COCOMO data sets (COC81, NASA93).
\ei
There is also some divergence in the features used to describe our data:
\bi
\item
The COC81 and NASA93 data sets all use the features defined by Boehm~\cite{boehm81}; e.g.
analyst capability, required software reliability, memory constraints, and use of software tools.
These datasets have also been translated from Boehm original COCOMO format into COCOMOII in order to 
add estimated defect and development length data for multiple goal optimizations.
\item
The other data sets use a wide variety of features including, number of entities in the data model, number of basic logical transactions, query count and number of distinct business units serviced.
\ei

