# Investigation on Self-Admitted Technical Debt in Open-Source Blockchain Projects
## 4 Results
### Comparison of SATD Detection Results in Blockchain Projects and in Open-Source Java Projects  
We compared the results previously reported with those contained in the reference research [11] for Java projects. The baseline study examines ten open source projects from different application domains, namely Ant, ArgoUML, Columba, EMF, Hibernate, JEdit, JFreeChart, JMeter, JRuby, and SQuirrel SQL. These selected projects are all written in JAVA. Table 11 reports the result of the SATD identification in this set of open-source project. The comparison between blockchain projects and Java projects allows deducing whether the blockchain projects are more or less exposed to the presence of SATD. This is useful for understanding whether blockchain projects are more or less threatened by TD. In particular, the main difference between the two sets of projects concerns, in addition to the technology used, the fact that blockchain projects are characterized by the need to generate trust--trust that resides in the code--in users as a fundamental requirement for their success. In both sets of projects, the presence of SATD is a sign of unpaid TD and can be a symptom of future difficulties in maintaining the project, which manifests itself in delays in fixing malfunctions and vulnerabilities. In blockchain projects, this is intolerable and would lead to a loss of trust and, therefore, project failure. First of all, some differences between the two sets of projects should be noted. First, unlike the baseline study, our selected blockchain projects contain source code written in several programming languages. Furthermore, the average number of contributors in blockchain projects is, on average, about five times higher than that of the Java projects examined in the benchmark study. Finally, the average percentage of comments filtered by us in the blockchain repositories is approximately 5%, while the average percentage of comments filtered in the reference study is 24%. The results of the SATD detection show that the blockchain repositories selected in this study have an average percentage of SATD in comments of 8.25%, which is therefore \begin{table}
\begin{tabular}{c c c} \hline \hline
**Concentration of Files with** & **Concentration of Files with** & **Concentration of Files with** \\
**SATD Less than 25\%** & **SATD between 25\% and 30\%** & **SATD over 30\%** \\ \hline Ethereum & Avalanche & Cardano \\ Terra & Solana & Polkadot \\ Usd coin & & Xrp \\ Binance & & Bitcoin \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Projects by the percentage of files with SATD. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Project** & **Files with SATD** &
\begin{tabular}{c} **Average Number of** \\ **SATD Comments** \\ **per File** \\ \end{tabular} & **Standard Deviation** \\ \hline Bitcoin & 406 & 3.59 & 5.26 \\ Ethereum & 1214 & 2.52 & 4.75 \\ Binance & 39 & 2.53 & 3.37 \\ Usd-coin & 60 & 2.26 & 2.63 \\ Solana & 570 & 4.38 & 11.37 \\ Xrp & 310 & 5.19 & 10.53 \\ Avalanche & 381 & 2.84 & 3.35 \\ Cardano & 406 & 3.57 & 4.01 \\ Terra & 88 & 2.10 & 3.27 \\ Polkadot & 960 & 4.59 & 10.69 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Distribution of SATD comments in files. higher than the percentage found in the repositories selected in the reference study, where this percentage is 5.52%. So blockchain projects have on average nearly 50% more SATD comments than projects selected by the reference study, and all blockchain projects have a higher SATD comment rate than the average percentage calculated in the reference projects. From these results, it can be deduced that blockchain projects could contain more TDs than the average of the reference projects, which could be detrimental to the long-term maintainability of the projects and therefore to the generation of trust. It should be noted that the reference projects are characterized by greater variability in the percentage of SATD, with a minimum SATD detection value of 2.05% of JEdit and a maximum of 14% of Hibernate, compared with the blockchain projects.