# Investigation on Self-Admitted Technical Debt in Open-Source Blockchain Projects
## 4 Results
### Classification Results  
Table 8 provides details on each of the projects analyzed in our study. The columns of the table show the results of the detection both in terms of the presence of SATD in the single comments and in terms of the presence of SATD in the files (where it is established that a file has SATD if at least one comment in it has been classified as SATD ).  
In general, the percentage of self-admitted technical debt for all blockchain projects is between 7.12% and 11.80% of comments, averaging 8.35%, with Terra and XRP projects having the highest percentage of SATD in comments, respectively 11.79% and 11.80% of comments. While the Ethereum and Bitcoin projects have the lowest percentages, at 7.13% and 7.72%, respectively. In all projects, the SATD classified as Design is more present than the SATD Requirement, and is on average about 4 times more present. However, the gap is more pronounced in projects like Binance and Terra where SATD Design is about 6.4 times more present, while it is smaller in Cardano where SATD Design is 1.9 times more present than the SATD Requirement. In terms of the percentage of files with SATD, the variation is more significant, ranging from 14.50% for Ethereum to 41.09% for Bitcoin, with an average of 23.02% of files where there is at least one comment classified as SATD. This means that among all the blockchain repositories, the Ethereum project has the lowest percentage of files containing SATD, while Bitcoin has the highest percentage of files containing SATD.  
Table 9 shows the distribution of comments with SATD in the respective project files, showing that in the SATD files, the average number of comments detected varies from 2.10 to 5.19. In correspondence with projects with higher averages, we can also notice higher standard deviation values, indicating a possible high concentration of SATD comments in a limited number of files.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Project**} & \multirow{2}{*}{\begin{tabular}{c} **Number of** \\ **Comments** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Number of** \\ **SATD** \\ **Design** \\ **Comments** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Number** \\ **SATD** \\ **Comments** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Percentage** \\ **of SATD** \\ **Comments** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Number of** \\ **Examined** \\ **Files** \\ **Files** \\ **Files** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Files with** \\ **SATD** \\ **with SATD** \\ \end{tabular} } \\ \hline Bitcoin & 17,887 & 1130 & 251 & 7.72\% & 988 & 406 & 41.09\% \\ Ethereum & 42,563 & 2486 & 546 & 7.13\% & 8334 & 1214 & 14.5\% \\ Binance & 1283 & 89 & 14 & 8.02\% & 174 & 39 & 22.4\% \\ Usd coin & 1533 & 109 & 28 & 8.93\% & 290 & 60 & 20.6\% \\ Solana & 27,520 & 1770 & 682 & 8.90\% & 2048 & 570 & 27.9\% \\ Xrp & 13,599 & 1316 & 289 & 11.80\% & 757 & 310 & 40.9\% \\ Avalanche & 11,880 & 870 & 176 & 8.80\% & 1472 & 381 & 25.9\% \\ Cardano & 24,112 & 1309 & 691 & 8.29\% & 2283 & 406 & 38.3\% \\ Terra & 1568 & 160 & 25 & 11.79\% & 542 & 88 & 16.2\% \\ Polkadot & 49,588 & 3023 & 1024 & 8.16\% & 2376 & 960 & 40.04\% \\ \hline Total & 191,533 & 12,262 & 3726 & & 19,264 & 4434 & \\ Average & 19,153.3 & 1226.2 & 372.6 & 8.35\% & 1926.4 & 443.4 & 23.02\% \\ \hline \hline \end{tabular}
\end{table}
Table 8: Results of SATD detecting in Blockchain projects.  
Based on the number of files with SATD, we can divide the projects into three sets. In particular, as reported in Table 10, four projects have a percentage of files with SATD lower than 25%, four projects have a percentage of files with SATD greater than 30%, while two projects have intermediate values.