Editorial: How to extend a conference paper to a journal paper

This issue contains two highly technical papers on fault prediction and model checking. Nonnegative sparse-based SemiBoost for software defect prediction, by Tiejian Wang, Zhiwu Zhang, Xiaoyuan Jing, and Yanli Liu, presents a novel semi-supervised learning technique to predict where faults could be in software. (Recommended by Giuliano Antoniol.) Past-Free[ze] reachability analysis: Reaching further with DAG-directed exhaustive state-space analysis, by Ciprian Teodorov, Luka Le Roux, Zoé Drey, and Philippe Dhaussy, presents a new algorithm to perform reachability analysis in model checkers that significantly reduces the state-space explosion problem. (Recommended by Ronald Olsson.) In a previous editorial, I set out STVR’s policy on extending conference papers to journal submissions [1]. The major requirements are that the journal version must have at least 30% new material, the journal version must include a citation to the conference paper, and the journal version must discuss the conference paper and summarize the new material. Here I suggest some practical guidelines for how to do the extension. The extension should start with four broad changes: