I have to analyse sequences of actions that look more or less like this JSON blob. The question I'm trying to answer is whether there are recurring (sub)patterns that different users adopt when asked to perform a certain specific task -- in this case, the task is to build a mathematical formula using this editor. In particular I'd like to know if there are multiple significantly different ways in which people build the same expression.
I thought of creating a Markov model, but that would only give me the most likely sequence of actions of length N. An obvious alternative would be to build trees and count how many times a certain path occurs in the dataset. However, the nature of the expression-building process means that the sequences can be polluted by many confounding, non-significant actions (such as streaks of UNDO-REDO, deleting symbols, and the likes).
I might go the "longest common subsequence" route, but I'm not sure that would tell me if there are "significantly different" ways of building the same expression (in quotes because, for now, I don't have a rigorous definition of "significantly different", but, for example, one way would be to drag and drop-in-place all the symbols in the correct order, and another way would be to drag all the symbols onto the canvas, and then place them in the correct spots).
I thought this might be a nice challenge for some AI algorithm, but I'm quite a noob at that, so I'm open to suggestions.