A common research dissemination practice is to expand a conference paper into a journal submission. This policy defines how the extension should be handled.
The usual rule of thumb is taken from common publisher guidelines: A new paper should have at least 30% significant new material. The new material is intended to be technical contribution, rather than background, related work, and motivation. The 30% is judged by the editors and reviewers. Note that this does not allow several conference papers to be combined into one journal paper—all results were previously published.
The journal submission should follow the following rules:
For more details, please see the editorial in the June 2016 issue of STVR.
Jeff Offutt and Rob Hierons