More models for thinking about plot.
Model 2-Plot as conflict: One writer, (sadly, I can't remember who) said that all you need to know for plot is "things get worse." Anytime in the story when you don't know what comes next, make things worse. Done well, this is true enough. Done wrong, it becomes "hit the bird." (Disney's Alladin. Don't know what to do, hit the bird.) As I said, done right it works. Things keep getting worse for Hero-Protagonist until at the end, they get better.
I prefer to think in terms of conflict. Plot is getting from point a to point b with the maximum amount of interesting and appropriate mayhem (conflict) in between. Your character wants or needs something (internal vs. external) and chooses to try or is forced to try to get it or to get away from having to get it. How that plays out, and what he or she loses or gains along the way is plot. This is a sort of hero's journey model.
Model 3-Plot as conflict part B; internal vs. external: In most fantasy fiction you will have a protagonist and an antagonist, or hero and villain. In conflict type B, the conflict and plot are driven by the opposing needs of the hero and the villain, remembering always that the villain is the hero of his or her own story. This leads us back to internally vs. externally driven plots.
Model 4-Plot as motion: In normal life, long periods go by without anything of significance happening. In fiction everything is a significant happening or should be. If it doesn't move the story somehow, it probably shouldn't be in the text. In plot as a motion we start at a point of stasis, or immediately after a point of stasis has been destabilized. The story then revolves around getting to a new point of stasis and this involves motion through the world and through time. Attempts to halt or redirect the flow of motion create the conflict necessary to interesting story-telling.
That's all for now. At least, for my brain, but I know y'all (including my esteemed Wyrdsmith colleagues) have all sorts of insights that I've missed, and I'd love to hear them. So, models 5-10? Sub clauses to the current list? Recipes for Plot Pie or Plot Stew? Rants about the anathema of pinning your poor characters to a plot board?