Going back and reading everything I can find from 2005, I have come to agree with you. This post seems especially telling if read closely. In the top right example of the previous post Jeff has shown an X-Cycle with two weak links and Bob then says:David P Bird wrote:Did he change his method later or is it because different authors have interpreted the term in their own ways working not from the original but from someone else's description I wonder.
His wording isn't ideal, but the idea is clearly there.Bob Hanson wrote:On the right we see that not all the connections in the chain have to be strong. We could have some "weak edges" anywhere we have "TRUE implies FALSE".
Lower in the same post he is pushing his 3D Medusa proposal and refers back to the undated link I gave earlier, http://www.stolaf.edu/people/hansonr/sudoku/top95-analysis.htm. That pushes the date on that page back to no later than Dec 2005.
Reading only the descriptive text at his top95 analysis leads you to a Sudopedia like definition of 3D Medusa, which is a mistake I made when I mentioned the page above. But as you pointed out, working through the examples makes it quite clear that he is including weak links bridging clusters from different pairs of colors.
Curiously, the Sudopedia page was written by Rudd in Nov 2006 (as can be seen at the WayBack Machine's copy of the Sudopedia update log for the page) with no mention of bridging. Yet in Oct 2006 Rudd had a description of 3D Medusa at his own site that explained bridging clusters as part of 3D Medusa.
Summing up, two factors jump out at me. First, many people who have learned 3D Medusa after 2007 will have gone by the Sudopedia description or another site's description copied from Sudopedia. Second, back in 2005 Bob Hansen clearly understood and give examples using weak links to bridge clusters, yet if you only read his descriptive text you could easily mistake that and miss out on bridging entirely.
