## 2 Materials and Methods
### Dataset
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & & & & & & & & & & & & & \\ \cline{2-13}
**Dataset Characteristics** & **CM1** & **JM1** & **KC1** & **KC3** & **MC1** & **MC2** & **MW1** & **PC1** & **PC2** & **PC3** & **PC4** & **PC5** \\ \hline Number of Instances (Modules) & 344 & 9591 & 2095 & 200 & 8737 & 125 & 263 & 735 & 1493 & 1099 & 1379 & 16962 \\ Number of Features & 37 & 21 & 21 & 39 & 38 & 39 & 37 & 37 & 36 & 37 & 37 & 38 \\ Programming Language & C & C & C++ & Java & C/C++ & C & C & C & C & C & C & C \\ \hline Feature Name & & & & & & & & & & & & \\ \hline LOC\_BLANK & x & x & x & x & x & x & x & x & x & x & x & x \\ BRANCH\_COUNT & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ CALI\_PAIRS & x & & & x & x & x & x & x & x & x & x & x & x \\ LOC\_CODE\_AND\_COMMENT & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ LOC\_COMMENTS & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ CONDITION\_COUNT & x & & & x & x & x & x & x & x & x & x & x & x \\ CYCLOMATIC\_COMPLEXITY & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ CYCLOMATIC\_DENSITY & x & & & x & x & x & x & x & x & x & x & x & x \\ DECISION\_COUNT & x & & & x & x & x & x & x & x & x & x & x \\ DECISION\_DENSITY & x & & & x & & & x & x & x & x & x & x & \\ DESION\_COMPLEXITY & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ DESION\_DENSITY & x & & & & x & x & x & x & x & x & x & x & x \\ EDGE\_COUNT & x & & & & x & x & x & x & x & x & x & x & x \\ ESSENTIAL\_COMPLEXITY & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ ESSENTIAL\_DENSITY & x & & & x & x & x & x & x & x & x & x & x & x \\ LOC\_EXECTUALE & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ PARAATER\_COUNT & x & & & x & x & x & x & x & x & x & x & x & x \\ HAISTER\_COUNT & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTER\_D\_OFFICULTY & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTER\_D\_OFFICULTY & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTERAD\_EFFORT & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTERAD\_ERROR\_EST & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTER\_LENGTH & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTER\_LEVEL & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTER\_PROG\_TIME & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ HAISTER\_VOLUME & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** & **X** \\ MAINTENANCE\_SEVERITY & x & & & x & x & x & x & x & x & x & x & x \\ \hline \hline \end{tabular}
\end{table} 
Table 1: A map of dataset characteristics and their features source-code static metrics for supporting cross–language and cross–project merging. A bold X with a dark gray background indicates the feature is present in all the datasets. Based on them, an assembled dataset was used to support the investigation of the cost-sensitive approach [40] regarding cross-project and cross-language in-organization generalizability. Its assembly was done by carefully merging the NASA MDP datasets. From the original NASA database, KC2 and KC4 were excluded due to significant feature discrepancies that could jeopardize the experiments. Thus, 12 NASA MDP datasets remained to be merged.