Rafael de Mello

Luiz Felipi Junionello, Rafael de Mello

The identification of code smells is largely recognized as a subjective task. Consequently, the automated detection tools available are insufficient to deal with the whole subjectivity involved in the task, requiring human validation. However, developers may follow different but complementary perspectives for manually validating the same code smell. Based on this scenario, our research aims at characterizing a comprehensive and optimized set of heuristics for guiding developers to validate the incidence of code smells reported by automated detection tools. For this purpose, we conducted an empirical study with 12 experienced software developers. In this study, we invited developers to individually validate the incidence of code smells in 24 code snippets from open-source Java projects. For each validation, developers should provide arguments for supporting their decisions. The study findings revealed that developers tend to look from different perspectives even when they agree about the incidence of a code smell. After coding the 303 arguments given into heuristics and refining them, we composed an optimized set of validation items for guiding developers on manually validating the incidence of eight types of code smells: data class, god class, speculative generality, middle man, refused bequest, primitive obsession, long parameter list, and feature envy. We are currently planning a survey with specialists for identifying opportunities for evolving the set of validation items proposed.

Rafael de Mello, Matheus Coelho

Context: Empirical studies in software engineering are typically centered on human subjects, ranging from novice to experienced developers. The experience of these individuals is a key context factor that should be properly characterized for supporting the design of empirical studies and interpreting their results. However, the criteria adopted for characterizing the experience of subjects do not follow a standard and are frequently limited. Goal: Our research aims at establishing an optimized and comprehensive scheme to characterize the subjects' experience for studies in software engineering. Method: Based on previous work, we defined the first version of this scheme, composed of three experience attributes, including time, number of projects, and self-perception. In the last years, we applied the characterization scheme over four empirical studies, reaching the characterization of 79 subjects in three different skills. Results: We found that the attributes from our scheme are positively but moderately correlated. This finding suggests these attributes play a complementary role in characterizing the subjects' experience. Besides, we found that study subjects tend to enumerate the technical diversity of their background when summarizing their professional experience. Conclusion: The scheme proposed represents a feasible alternative for characterizing subjects of empirical studies in the field. However, we intend to conduct additional investigations with developers to evolve it.

Marco Torchiano, Daniel Méndez Fernández, Guilherme Horta Travassos et al.

Context: Surveys constitute an valuable tool to capture a large-scale snapshot of the state of the practice. Apparently trivial to adopt, surveys hide, however, several pitfalls that might hinder rendering the result valid and, thus, useful. Goal: We aim at providing an overview of main pitfalls in software engineering surveys and report on practical ways to deal with them. Method: We build on the experiences we collected in conducting many studies and distill the main lessons learnt. Results: The eight lessons learnt we report cover different aspects of the survey process ranging from the design of initial research objectives to the design of a questionnaire. Conclusions: Our hope is that by sharing our lessons learnt, combined with a disciplined application of the general survey theory, we contribute to improving the quality of the research results achievable by employing software engineering surveys.