The Scothorn Model was a proposal to change the way Spacesim's Administration hierarchy was organized. Specifically, it suggested that the two individuals who act as Spacesim's Club Heads are not necessarily the two Mission Commanders. The Scothorn Model was unintentionally implemented in 2009-10, when there was an Engineering Commander in addition to the Mission Commander and Education Commander. The next year, the Scothorn Model was arguably the strongest influence on the 2010 Proposal to Change the Hierarchy, and the subsequent 2011 hierarchy changes.
Since its founding, Spacesim has been led by the Mission Commanders. An arguably regrettable result of this is that Spacesim's focus tends towards the Mission rather than the educational side of things. The Scothorn model (which, as the name suggests, was formulated by Jonathan Scothorn in 2007) would ensure that the two Club Heads are those out of the six Commanders who have the best leadership abilities. One result of this would be that the mission is just as important as the other aspects of Spacesim; another would be that those who wish to be in leadership positions are not required to apply as Mission Commander, but can instead apply for whichever position interests them most.
The Evans Model
The Evans Model was a modification to the Scothorn Model proposed by Lyra Evans shortly after the Scothorn Model was brought to table. The Evans Model would have one of each of the branches of Spacesim (Mission, EEPs, and Planetariums) have its own representative as co-head of the club. Thus there would be three co-heads instead of the two proposed in the Scothorn Model.