A process that has at least two material entities as participants that have an effect upon one another.

In the original definition, INO developers define this class with respect to interactors involved in the interaction process. INO includes the classes “interactor” and “interactor role” (see SeeAlso note). Here, we generalize this definition, excluding reference to interactors. In the context of SCO, we aim to provide users with an upper-level class that generally points to the involvement of material entities in an interaction process mutually influencing each other. We suggest not using this class directly but, instead, extending SCO-provided subclasses as needed. We wish users to classify interactions according to whether they occur among system components, among system environment components, or between system and system environment components. Original definition: “Interaction is a processual entity that has two or more participants (i.e., interactors) that have an effect upon one another.”