The world changes

This issue is the first issue of STVR since Jeff Offutt stood down as joint Editor-in-Chief. Jeff was Editor-in-Chief and then joint Editor-in-Chief from 2007 to 2019. This has been an interesting and challenging period for academic journals, with many changes to how journals operate. During this period, Jeff significantly strengthened the journal and has been at the forefront of developments within the field. As Jeff mentioned in the last editorial, there are still many challenges, but Jeff has left STVR in an excellent position. I also hope that we will soon start receiving his papers again! On a personal note, I was honoured when Jeff invited me to be joint EiC, and I welcomed the opportunity to work with him. I accepted immediately and have never regretted the decision. It has been a pleasure to work with Jeff: not only is he a major figure in the field, he is also charming and humble. Jeff also genuinely cares about the discipline and those working within it. As an example, he has spent a significant amount of time providing invaluable advice to junior researchers and students. Although I was sad to see Jeff step down, I am really pleased to be able to welcome Professor Tao Xie as joint Editor-in-Chief of STVR. I first met Tao at a conference (some years ago), and I was immediately impressed by him as a person but also by the work of his that we discussed. This work addressed a real problem in a practical manner but was also based on sound intuition and theory. He has since become a leading figure in the field. Jeff and I were convinced that Tao was the right person to take over and were delighted when he accepted our invitation. Tao has already shown great energy and enthusiasm, and in his upcoming editorial, he will say a little more about some of the ideas of his that we will be implementing. This issue contains two papers. Our first paper is “An Improved Software Reliability Prediction Model by Using High Precision Error Iterative Analysis Method” by Gul Jabeen, Ping Luo and Wasif Afzal (recommended by Min Xie). This concerns a classical problem, which is that of trying to model how the reliability of a piece of software will change during development. Techniques that achieve this can, for example, be used to help plan the software release. The authors use neural networks to help model the error and so make a model more accurate. One of the benefits of the approach is that it can potentially be used with any parametric software reliability prediction model. The second paper is “An End-user-centric Test Generation Methodology for Performance Evaluation of Mobile Networked Applications” by Mustafa Al-tekreeti, Atef Abdrabou and Kshirasagar Naik (recommended by Jane Hayes). The paper concerns the testing of mobile network applications, with a focus on performance (waiting time delay) and its impact on user experience. The authors introduce new test coverage criteria associated with two types of delays and also use metamorphic testing to address the oracle problem.