In this issue

In this issue we have nine regular research papers. The first four papers are all concerned with aspects of quality models and quality attributes, whereas the next four all look at various aspects of software testing. The final paper in his issue is concerned with software process models, particularly hybrid agile models. In ‘‘The COCA quality model for user documentation’’, Bartosz Alchimowicz and Jerzy Nawrocki propose a new quality model for user documentation together with a set of acceptance criteria. The model has just four quality characteristics (Completeness, Operability, Correctness, and Appearance). The model has been validated using nine user manuals taken from the educational software domain. High-quality user documentation must be readable, and this is also an important attribute of high-quality software. The paper ‘‘Beauty and the Beast—On the Readability of Object-Oriented Example Programs’’, by Jürgen Börstler, Michael E Caspersen, and Marie Nordström discusses the quality attributes of simplicity and understandability from a cognitive perspective. The authors show how to measure these attributes and validate the measures using programs taken from 12 popular introductory Java programming textbooks. It is suggested that readability is a sub-factor of understandability, and a measure, the Software Readability Ease Score, is proposed and compared with other readability measures with good results. The measure could be used to give students immediate feedback on the readability of their programs. In ‘‘Software quality improvement: a model based on managing factors impacting software quality’’, Ivan Janicijevic, Maja Krsmanovic, Nedeljko Zivkovic, and Sasa Lazarevic propose a systematic framework for modelling the processes of a quality management system stochastically and show how to select the optimum set of factors for software quality improvement. The methodology allows managers to identify those areas in which efforts to improve quality will be particularly effective.