Measures of Association—How to Choose Suppose you wish to study the relationship between two variables by using a single measure or coefficient. There are many considerations that go into selecting an optimum measure of associa-tion; these are briefly discussed in the Summary section. For simplification, we base our selection of an appropriate measure exclusively on what type of variable we , *Process shown may differ depending on journal. Follow the instructions that are given during submission to your chosen journal, Open-access archives and journals are both practical and lawful. Implementations around the world are proving that they surpass traditional subscription-based journals in their cost-effectiveness and service to science and scholarship. Join the growing, worldwide movement to bring the benefits of open access to all., Trajectory network edges are then directed so that their sources have a lower tem-poral score than their targets, indicating a transition from an early cell type to a later cell type. The trajectory is visualized using the Sugiyama hierarchical layout algorithm [20]., Access the manuscript template from the author kit (conferences), from the peer-review manuscript submission system (journals), or from the Author Resources webpage under Templates (conferences or journals). Fill in the manuscript information by typing directly over the elements in the template. Styles have been built into the template., .