Context

The cornerstones of technical debt (TD) are two concepts borrowed from economics: principal and interest. Although in economics the two terms are related, in TD there is no study on this direction so as to validate the strength of the metaphor.

Objective

We study the relation between Principal and Interest, and subsequently dig further into the ‘ingredients’ of each concept (since they are multi-faceted). In particular, we investigate if artifacts with similar levels of TD Principal exhibit a similar amount of TD Interest, and vice-versa.

Method

To achieve this goal, we performed an empirical study, analyzing the dataset using the Mantel test. Through the Mantel test, we examined the relation between TD Principal and Interest, and identified aspects that are able to denote proximity of artifacts, with respect to TD. Next, through Linear Mixed Effects (LME) modelling we studied the generalizability of the results.

Results

The results of the study suggest that TD Principal and Interest are related, in the sense that classes with similar levels of TD Principal tend to have similar levels of Interest. Additionally, we have reached the conclusion that aggregated measures of TD Principal or Interest are more capable of identifying proximate artifacts, compared to isolated metrics. Finally, we have provided empirical evidence on the fact that improving certain quality properties (e.g., size and coupling) should be prioritized while ranking refactoring opportunities in the sense that high values of these properties are in most of the cases related to artifacts with higher levels of TD Principal.

Conclusions

The findings shed light on the relations between the two concepts, and can be useful for both researchers and practitioners: the former can get a deeper understanding of the concepts, whereas the latter can use our findings to guide their TD management processes such as prioritization and repayment.

中文翻译：

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探索技术债务本金与利息之间的关系：一种经验方法

语境

技术债务（TD）的基石是从经济学中借来的两个概念：本金和利息。尽管在经济学中这两个术语是相关的，但在TD中没有研究此方向以验证隐喻的强度。

目的

我们研究了本金和利益之间的关系，随后进一步研究了每个概念的“成分”（因为它们是多方面的）。特别是，我们调查TD主体水平相似的工件是否显示出类似的TD利益量，反之亦然。

方法

为了实现此目标，我们进行了一项实证研究，使用Mantel检验分析了数据集。通过Mantel测试，我们检查了TD本金和兴趣之间的关系，并确定了能够表示与TD有关的伪影的方面。接下来，通过线性混合效应（LME）建模，我们研究了结果的推广性。

结果

研究结果表明，从具有相同水平的TD Principal的类趋向于具有相似的兴趣水平的意义上来说，TD Principal和Interest是相关的。此外，我们得出的结论是，与孤立的指标相比，TD本金或利息的汇总指标更能够识别附近的伪像。最后，我们提供了以下事实的经验证据：在优先考虑重构机会的同时，应优先考虑改进某些质量属性（例如大小和耦合），因为这些属性的高值在大多数情况下与较高级别的工件有关TD校长。

结论

研究结果阐明了这两个概念之间的关系，对研究人员和从业人员都可能有用：前者可以对概念有更深入的了解，而后者可以使用我们的发现来指导他们的TD管理流程，例如确定优先顺序和还款。