and Karen A. Foss in their book Theories of Human Communication (tenth edition) describe a type of logical force called contextual force. Contextual force causes a person to follow a form of logic that leads one to believe that an action or interpretation is a direct result of, and is appropriate to, the context. For example, "How else could I have reacted?" or "Naturally I acted that way, it was appropriate to the situation" leads to the mentality of "I did what I had to do." Secondly, in CMM, contexts are extremely important, and they are not static and unchanging. For example, a relationship that is longstanding can contextualize the episode of an ugly argument as something unpleasant but unavoidable. The couple will most likely worth though this ugly argument because of their relationship contextualizing the episode. However, an episode of an ugly argument can contextualize a relationship if a couple is on their first date. Therefore, the argument is more likely to contextualize the relationship is over or not worth pursuing. What contextualizes what in the hierarchy of organized meanings overlaps and is interlinked in a complicated hierarchy of meanings which can shift at any moment. The hierarchy of meaning model addresses questions of: "what are the different contexts that are happening simultaneously?, which layers are most foregrounding or relevant?, how are they shifting as you share your story?, and how might I be personalizing this too much or not enough?". Serpentine model The CMM theorists take the hierarchy model a step further by reinforcing the importance of interaction and adding the aspect of time. Pearce stresses that communication cannot be done alone and that furthermore, this usually occurs before or after another's actions. Therefore, understanding past events and their impact on individuals is essential to improving communication. This new model is called the serpentine model and visually demonstrates how communication is a back and forth interaction between participants rather than just a simple transmission of information. This model addresses questions of: "what do I want to make in the next turn?, how am I marking the beginning and end of this episode?, and how would it be different if I went further back or further forward?". Charmed and strange loop The embedded contexts illustrated in the hierarchy model represent a stable hierarchy. It suggests that higher levels subsume lower levels. Meanwhile, sometimes "lower levels can reflect back and