# On the Relationship between Self-Admitted Technical Debt Removals and Technical Debt Measures
## 4 Results
#### 4.1.4 Relationship between Change Type of Commit Removal and File not Found
The last case (NA) is one in which the value of all the metrics described above remained unchanged, or there was an equal number of improved and worsened metrics, or again, there was no change in the value of the TD among the two successive commits; therefore, it was not possible to catalog. For each project, Table 7 reports the number of cases in which (1) the TD has improved and the metrics have deteriorated, (3) both TD and metrics have deteriorated, and (4) the TD has deteriorated, but the metrics have improved, and (5) other cases not considered. For Log4j, for 19.12% of the cases (13), the result produced by SonarQube was validated, since an improvement in the Technical Debt measure was matched by an improvement in the majority of the metrics taken into consideration. For 8.82% of the cases (6), the result was not validated, as an \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & **\#Files** & **\#Files** & **\#Files** & **\#Files** & **\#Files** \\ \multirow{2}{*}{**Project**} & **TD Improved \&** **TD Improved but** & **Both TD and Metrics** & **TD Got Worse but** & **\#Files** \\  & **Metrics Improved** & **Metrics Got Worse** & **Got Worse** & **Metrics Improved** & **NA** \\ \hline
**Log4j** & 13 & 6 & 12 & 1 & 36 \\ \hline
**Gerrit** & 7 & 6 & 10 & 10 & 45 \\ \hline
**Hadoop** & 12 & 2 & 13 & 11 & 88 \\ \hline
**Tomcat** & 38 & 15 & 11 & 12 & 135 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Metrics analysis. TD: technical debt. Figure 5: Overview of the change type percentage when the file is not found. improvement in the value of the TD was accompanied by a worsening of most of the metrics considered. However, for 1.47% of cases (1), the non-improvement of the TD value had a positive side effect, improving most of the metrics considered. However, for 17.65% of the cases (12), in addition to the non-improvement of the TD, there was also a worsening of the majority of the metrics taken into consideration. Finally, for 52.94% of cases (36), it was not possible to make considerations. For Gerrit, in most cases, 12.82% (10 cases) of developers' actions do not cause an improvement in the TD but hurt both the TD and the metrics. With the same percentage, there is a worsening of the TD, but at the same time, there was a considerable improvement of the metrics. Only in 8.97% of cases (7) did the results show an improvement of both values under observation, while in 7.69% of cases (6), there was an improvement in TD but a worsening of metrics. For the remaining 57.69% of cases (45), it was not possible to express considerations. Therefore, it is observed that the cases in which conclusions cannot be drawn represent a significant percentage. For Hadoop, the table shows that for 9.52% of cases (12), an improvement in technical debt was accompanied by an improvement in at least one of the metrics considered. In 1.59% of cases (2), an improvement in the value of TD was accompanied by deterioration in at least one of the metrics considered, and none of them improved. For 8.73% of cases (13), the developers' actions did not lead to any improvement in the value of the TD but improved most of the metrics considered, thus obtaining a positive effect on them. For 10.32% of cases (11), there was not an improvement in TD combined with a worsening of the metrics examined. Finally, in 69.84% of cases (88), it was not possible to take these factors into consideration. Tomcat also confirms the trend of the previous cases; in fact, the highest percentage belongs to the case where no consideration was possible, 64% (135 cases). This percentage was followed with 18% (38) cases in which both the TD value and metrics improved, and with 7.10% of cases (15) in which there was an improvement in the TD value and at the same time a worsening of the metrics. Finally, in 5.69% of cases, (12) there is a worsening of both values, and for 5.21% of cases (11), the TD worsens but the metrics improve. Figure 6 depicts the data about the trend of the TD value and the CK metrics.