That's step 2. Step 1 is using contrived examples with clear differences in structure. You need to start small like this because in order to answer the basic questions, you need to eliminate experimental variables. That way, you can establish basic principles for how people tend to build up an understanding of code.

Then you can move on to what we're really interested in: how do people build an understanding of complex applications with many interacting parts? But you can't go there first; if you do, you won't be able to interpret your results because there will be just as many fundamental questions as experimental variables.