the best way to measure and compare different off-chain scaling solutions

Hey guys!

Recently, I read lots of different articles about scaling solutions and in the next semester, I have the opportunity to make my thesis about this topic.

My first idea about it is that it is easier and more obvious to focus on only off-chain scaling solutions on top of Ethereum. My personal opinion is that it is really hard to define the set of on-chain scaling solutions and the comparison and the measurement will be harder because usually, these different approaches mean different blockchain ecosystems.

My plan is to choose implementations from each different off-chain scaling type (sidechains, validiums, plasma chains, optimistic rollups, zero-knowledge rollups, and state channels) and compare them to each other. The comparison is based on security, decentralization, and scalability examination.

The decentralization examination is based on three metrics Gini coefficient, Shannon entropy, and Nakamoto coefficient. The scalability examination is based on the transaction cost, throughput and latency. Maybe, I could also examine the message and time complexity like in a distributed system. I do not know what will be the best metric for security yet.

What do you think is the best way to compare different off-chain solutions from security, scalability, and decentralization points of view? And what is your about this kind of paper?

Thanks in advance!