Structured Review of the Evidence for Effects of Code Duplication on Software Quality

This report presents the detailed steps and results of a structured review of code clone literature. The aim of the review is to investigate the evidence for the claim that code duplication has a negative effect on code changeability. This report contains only the details of the review for which there is not enough place to include them in the companion paper published at a conference (Hordijk, Ponisio et al. 2009 - Harmfulness of Code Duplication - A Structured Review of the Evidence)

How We Know the Practical Impact of Clone Analysis

In order to develop and improve clone analysis techniques for industrial application, it is necessary to know about how those techniques provide impacts on clone management in industry. In this position paper, we discuss approaches to observing the practical impact of clone analysis on the basis of our experience in applying clone analysis into an industrial development process

Evaluating the relation between changeability decay and the characteristics of clones and methods

In this paper we propose a methodology to evaluate if there is a relation between two code characteristics. The methodology is based on relative risk, an epidemiology formula used to analyze the effect of toxic agents in developing diseases. We present a metaphor in which the disease is changeability decay, measured at method level, and the toxic agent is a source code characteristic considered harmful. However, the formula assesses the strength of the relation between any toxic agent and any disease. We apply the methodology to explore cloning as a toxic agent that increases the risk of changeability decay. Cloning is a good agent to analyze given that although there is some evidence of maintainability issues caused by clones, we do not know which clones are harmful, or to what extent. We compare cloning with other possible 'toxic agents', like having high complexity or having high fan-in. We also use the technique to evaluate which clone characteristics (like clone size) may indicate harmful clones, by testing such characteristics as toxic agents. We found that cloning is one of the method characteristics that affects the least changeability decay, and that none of the clone characteristics analyzed are related with changeability decay

Towards an Analysis of Who Creates Clone and Who Reuses it

Code clone analysis is valuable because it can reveal reuse behaviours efficientlyfrom software repositories. Recently, some code reuse analyses using clonegenealogies and code clones over multiple projects were conducted. However, mostof the conventional analyses do not consider the developers’ individual difference toreuse behaviors. In this paper, we propose a method for code reuse analysis whichtakes particular note of the differences among individuals. Our analysis methodclarifies who reused whose source code across multiple repositories. We believethe result might provide us with constructive perceptions such as characteristics ofreused code itself by multiple developers, and developers who implement reusablecode

Structured Review of Code Clone Literature

This report presents the results of a structured review of code clone literature. The aim of the review is to assemble a conceptual model of clone-related concepts which helps us to reason about clones. This conceptual model unifies clone concepts from a wide range of literature, so that findings about clones can be compared with each other