Preliminary guidelines for empirical research in software engineering

Empirical software engineering research needs research guidelines to improve the research and reporting processes. We propose a preliminary set of research guidelines aimed at stimulating discussion among software researchers. They are based on a review of research guidelines developed for medical researchers and on our own experience in doing and reviewing software engineering research. The guidelines are intended to assist researchers, reviewers, and meta-analysts in designing, conducting, and evaluating empirical studies. Editorial boards of software engineering journals may wish to use our recommendations as a basis for developing guidelines for reviewers and for framing policies for dealing with the design, data collection, and analysis and reporting of empirical studies.     

The repertory grid technique: Its place in empirical software engineering research

Personal construct theory (applied via the repertory grid technique) supports interpretivist research in a structured manner and, as such, has relevance for researchers conducting studies focused on the human and organisational aspects of software engineering. Personal construct theory (which underpins the repertory grid technique) is introduced, and the technique and its administration is discussed. Research studies from the literature are reviewed to provide illustrative examples of its application within a software engineering context. Since any research approach needs to answer questions about its reliability and validity within a particular study, these issues are considered for repertory grid investigations and criteria are offered that can be used to judge these issues within a planned, and/or reported, study.     

Using mapping studies as the basis for further research - A participant-observer case study

Context

We are strong advocates of evidence-based software engineering (EBSE) in general and systematic literature reviews (SLRs) in particular. We believe it is essential that the SLR methodology is used constructively to support software engineering research.

Objective

This study aims to assess the value of mapping studies which are a form of SLR that aims to identify and categorise the available research on a broad software engineering topic.

Method

We used a multi-case, participant-observer case study using five examples of studies that were based on preceding mapping studies. We also validated our results by contacting two other researchers who had undertaken studies based on preceding mapping studies and by assessing review comments related to our follow-on studies.

Results

Our original case study identified 11 unique benefits that can accrue from basing research on a preceding mapping study of which only two were case specific. We also identified nine problems associated with using preceding mapping studies of which two were case specific. These results were consistent with the information obtained from the validation activities. We did not find an example of an independent research group making use of a mapping study produced by other researchers.

Conclusion

Mapping studies can save time and effort for researchers and provide baselines to assist new research efforts. However, they must be of high quality in terms of completeness and rigour if they are to be a reliable basis for follow-on research.     

Six years of systematic literature reviews in software engineering: An updated tertiary study

Context

Since the introduction of evidence-based software engineering in 2004, systematic literature review (SLR) has been increasingly used as a method for conducting secondary studies in software engineering. Two tertiary studies, published in 2009 and 2010, identified and analysed 54 SLRs published in journals and conferences in the period between 1st January 2004 and 30th June 2008.

Objective

In this article, our goal was to extend and update the two previous tertiary studies to cover the period between 1st July 2008 and 31st December 2009. We analysed the quality, coverage of software engineering topics, and potential impact of published SLRs for education and practice.

Method

We performed automatic and manual searches for SLRs published in journals and conference proceedings, analysed the relevant studies, and compared and integrated our findings with the two previous tertiary studies.

Results

We found 67 new SLRs addressing 24 software engineering topics. Among these studies, 15 were considered relevant to the undergraduate educational curriculum, and 40 appeared of possible interest to practitioners. We found that the number of SLRs in software engineering is increasing, the overall quality of the studies is improving, and the number of researchers and research organisations worldwide that are conducting SLRs is also increasing and spreading.

Conclusion

Our findings suggest that the software engineering research community is starting to adopt SLRs consistently as a research method. However, the majority of the SLRs did not evaluate the quality of primary studies and fail to provide guidelines for practitioners, thus decreasing their potential impact on software engineering practice.     

A checklist for integrating student empirical studies with research and teaching goals

The use of empirical studies with students in software engineering helps researchers gain insight into new or existing techniques and methods. However, due mainly to concerns of external validity, questions have been raised about the value of these types of studies. The authors of this paper draw on their experiences of conducting a large number of empirical studies in university courses in three countries (Italy, Norway, and the United States) to address this important issue. This paper first identifies the requirements that research and pedagogy place on a valid empirical study with students. This information is then used as the basis for a checklist that provides guidance for researchers and educators when planning and conducting studies in university courses. The goal of this checklist is to help ensure that these studies have as much research and pedagogical value as possible. Finally, an example application of the checklist is provided to illustrate its use.     

Empirical Research in Software Engineering — A Literature Survey

Empirical research is playing a significant role in software engineering (SE), and it has been applied to evaluate software artifacts and technologies. There have been a great number of empirical research articles published recently. There is also a large research community in empirical software engineering (ESE). In this paper, we identify both the overall landscape and detailed implementations of ESE, and investigate frequently applied empirical methods, targeted research purposes, used data sources, and applied data processing approaches and tools in ESE. The aim is to identify new trends and obtain interesting observations of empirical software engineering across different sub-fields of software engineering. We conduct a mapping study on 538 selected articles from January 2013 to November 2017, with four research questions. We observe that the trend of applying empirical methods in software engineering is continuously increasing and the most commonly applied methods are experiment, case study and survey. Moreover, open source projects are the most frequently used data sources. We also observe that most of researchers have paid attention to the validity and the possibility to replicate their studies. These observations are carefully analyzed and presented as carefully designed diagrams. We also reveal shortcomings and demanded knowledge/strategies in ESE and propose recommendations for researchers.     

Successfully completing case study research: combining rigour, relevance and pragmatism

The organizational and social issues associated with the development, implementation and use of computer-based information systems have increasingly attracted the attention of information systems researchers. Interest in qualitative research methods such as action research, case study research and ethnography, which focus on understanding social phenomena in their natural setting, has consequently grown. Case study research is the most widely used qualitative research method in information systems research, and is well suited to understanding the interactions between information technology-related innovations and organizational contexts. Although case study research is useful as a means of studying information systems development and use in the field, there can be practical difficulties associated with attempting to undertake case studies as a rigorous and effective method of research. This paper addresses a number of these difficulties and offers some practical guidelines for successfully completing case study research. The paper focuses on the pragmatics of conducting case study research, and draws from the discussion at a panel session conducted by the authors at the 8th Australasian Conference on Information Systems, September 1997 (ACIS 97), from the authors' practical experiences, and from the case study research literature.     

Identifying relevant studies in software engineering

Context

Systematic literature review (SLR) has become an important research methodology in software engineering since the introduction of evidence-based software engineering (EBSE) in 2004. One critical step in applying this methodology is to design and execute appropriate and effective search strategy. This is a time-consuming and error-prone step, which needs to be carefully planned and implemented. There is an apparent need for a systematic approach to designing, executing, and evaluating a suitable search strategy for optimally retrieving the target literature from digital libraries.

Objective

The main objective of the research reported in this paper is to improve the search step of undertaking SLRs in software engineering (SE) by devising and evaluating systematic and practical approaches to identifying relevant studies in SE.

Method

We have systematically selected and analytically studied a large number of papers (SLRs) to understand the state-of-the-practice of search strategies in EBSE. Having identified the limitations of the current ad-hoc nature of search strategies used by SE researchers for SLRs, we have devised a systematic and evidence-based approach to developing and executing optimal search strategies in SLRs. The proposed approach incorporates the concept of ‘quasi-gold standard’ (QGS), which consists of collection of known studies, and corresponding ‘quasi-sensitivity’ into the search process for evaluating search performance.

Results

We conducted two participant-observer case studies to demonstrate and evaluate the adoption of the proposed QGS-based systematic search approach in support of SLRs in SE research.

Conclusion

We report their findings based on the case studies that the approach is able to improve the rigor of search process in an SLR, as well as it can serve as a supplement to the guidelines for SLRs in EBSE. We plan to further evaluate the proposed approach using a series of case studies on varying research topics in SE.     

Systematic literature reviews in software engineering – A tertiary study

ContextIn a previous study, we reported on a systematic literature review (SLR), based on a manual search of 13 journals and conferences undertaken in the period 1st January 2004 to 30th June 2007.ObjectiveThe aim of this on-going research is to provide an annotated catalogue of SLRs available to software engineering researchers and practitioners. This study updates our previous study using a broad automated search.MethodWe performed a broad automated search to find SLRs published in the time period 1st January 2004 to 30th June 2008. We contrast the number, quality and source of these SLRs with SLRs found in the original study.ResultsOur broad search found an additional 35 SLRs corresponding to 33 unique studies. Of these papers, 17 appeared relevant to the undergraduate educational curriculum and 12 appeared of possible interest to practitioners. The number of SLRs being published is increasing. The quality of papers in conferences and workshops has improved as more researchers use SLR guidelines.ConclusionSLRs appear to have gone past the stage of being used solely by innovators but cannot yet be considered a main stream software engineering research methodology. They are addressing a wide range of topics but still have limitations, such as often failing to assess primary study quality.