> If research on highlighting for natural language can be transferred to code (I'm not entirely sure, but I suspect it might), highlighting might actually be harmful to comprehension.
Interesting. Could you share some of that research and its conclusions?
I don't remember whose research it is (it's a bit removed from my field of expertise =), but the gist of it is that they tried to highlight different parts of speech in running text in different colours, and showed that it actually decreased reading speed and comprehension.
Of course, there are several possible error sources (unfamiliarity with the colouring scheme for example), and whether this can be transferred to reading code is an open question. But I still think it's important to keep the existence of this kind of research in mind when discussing this kind of question (and also the similar question of mouse-driven interfaces vs. keyboard shortcuts), as it easily devolves into strongly held opinions and arguments along the lines of "it stands to reason that $opinion-held-is-true"
I've always considered those kinds of studies suspect. When I'm reading, human-language text, I spend most of the time going forward. Maybe I'll skip to an earlier part of the sentence if it turns out to be a garden-path parsing, or to a previous sentence to re-acquaint myself with context. Those are exceptional cases.
In code, I'm frequently tracing back and forth through a block, looking for specific information in different lines. I think that the coloration helps to provide "landmarks" for non-linear traversal of the code. I'd consider color-free code to be more similar to un-punctuated text, than I would consider colored text to be to colored code.
Interesting. Could you share some of that research and its conclusions?