Denis Kozlov

Analysis and Validation of Learning Technology Models, Standards and Specifications: The Reference Model Analysis Grid RMAG

The paper presents a model for the analysis, comparison and validation of standards, specifications and in particular reference models in the field of Technology Enhanced Learning TEL. The Reference Model Analysis Grid RMAG establishes categories of reference models and standards. Based on those categories, a set of criteria for the analysis and validation of standards was elaborated as a part of the ICOPER project that aims at interoperable open content for competency-based TEL. The analysis of standards in this context is targeted at developing a set of validated approaches that lead to a new reference model. Four standards were investigated, taking into account a broad range of aspects like practical and semantic interoperability and integration issues. In the case study, the authors analyzed both, the standards and specifications and the usefulness of the RMAG. The results of this case study can be used for further analyses of TEL standards as well as for reference models targeted at interoperability.

Exploratory Analysis of the Relations between Code Cloning and Open Source Software Quality

In recent literature there is still a lack of understanding how the reuse and cloning of software affects its quality. The focus of this study is to analyze the relationships between source code cloning and software quality for the case of open source software project forks (SPFs) as a kind of software reuse. In total 117 releases related to three generations of eight eMule SPFs were scrutinized. Software quality was measured in terms of internal quality attributes. The tools CCFinderX and SoftCalc were used to measure code cloning metrics and internal quality attributes, respectively. In total 8 code cloning metrics and 71 internal quality attributes were analyzed. The quantitative relationships between the code cloning metrics and internal quality attributes were identified based on Pearson product moment correlation analysis. Our results revealed a number of important relationships between the metrics under study.

Fault-proneness of open source software: Exploring its relations to internal software quality and maintenance process

The goal of this study is to explore how fault-proneness of open source software (OSS) could be explained in terms of internal quality attributes and maintenance process metrics. We reviewed earlier studies and performed a multiple case study of eight Java-based projects based on data available in the Source Forge repository. Overall, we studied 342 re- leases of those systems. As is usual, software quality was regarded as a set of internal and external quality attributes. A to- tal of 76 internal quality attributes were measured from the source code of the selected systems via the tool SoftCalc. Two external quality attributes contributing to fault-proneness were in turn obtained from the Source Forge Issue Tracking Sys- tem. The framework for assessing the maintenance process was adopted from our previous studies. Its distinguishing fea- ture is that it takes into account the peculiarities of OSS development. We included 23 maintenance process metrics to this study. Relationships between the metrics under study were identified by means of correlation analysis, multiple regression analysis and factor analysis. The obtained results give an interesting insight into interpretation of the earlier results of other researchers, regarding especially their generalizability. The strengths of our study include the following: 1) we stud- ied a greater number of metrics than most of the related studies, 2) we studied a greater number of OSS-systems than most of the studies, and 3) we focused on the fault-proneness of modern Java-based systems and investigated them as an aggre- gated sample.

An Exploratory Empirical Study of Internal Quality Attributes of Open Source Software Systems

This exploratory empirical study has focused on open source software (OSS). Seven medium-sized OSS systems from the SourceForge repository were analysed. Over 100 internal quality attributes and programming practices were scrutinized by using two semi-automated source code analysis tools (FindBugs and SoftCalc). Many statistically significant relations were revealed by the conducted regression analyses. Seven so-called bad programming practices; as manifested by the measured source code inconsistencies were identified as having significant relations to internal software quality. Additionally we set and tested two hypotheses. That investigation provided mixed results partly supporting some of the earlier findings between software size and potential maintenance problems; especially related to some of the programming practices.

Software and Standards in an Emerging Domain

This paper considers the software market in the field of e-Learning and Technology Enhanced Learning (TEL) through observing standardization developments in the domain. A model of software market evolution suggests that observations on development and deployment of standards in the domain indicate the status on the market. As the model holds, in a mature phase, level of standardization is high and the number of competing standards low. The result of the study is, there appears to be a market, but a heterogeneous one, with hesitation on dominant designs and an overall modest level of standards adoption. Content standardization enables the (re)use of the learning content in multiple formats with diverse learning management systems (LMS), virtual learning environments (VLEs), learning platforms, HRM and administration systems. A number of initiatives to develop specifications or standards exist. Competing standards or specifications are found for most target areas. Efforts to establish common frameworks and reference models have emerged. Such overall consensus frameworks will support developments towards content interoperability in this vertical as they have in other domains.