Modeling How Programmers Read Code 115
An anonymous reader writes "Following up on an experiment from December, Michael Hansen has recorded video of programmers of varying skill levels as the read and evaluate short programs written in Python. An eye tracker checks 300 times per second to show what they look at as they mentally digest the script. You can see some interesting differences between experts and beginners: 'First, Eric's eye movements are precise and directed from the beginning. He quickly finds the first print statement and jumps back to comprehend the between function. The novice, on the other hand, spends time skimming the whole program first before tackling the first print. This is in line with expectations, of course, but it's cool to see it come out in the data. Another thing that stands out is the pronounced effect of learning in both videos. As Eric pointed out, it appears that he "compiled" the between function in his head, since his second encounter with it doesn't require a lengthy stop back at the definition. The novice received an inline version of the same program, where the functions were not present. Nevertheless, we can see a sharp transition in reading style around 1:30 when the pattern has been recognized.'"
Invalid results? (Score:4, Insightful)
The code between these two individuals is completely different, even if it produces the same results. How do you discern any meaningful results out of two people reading two different sets of code?
Re:don't give PHB's any ideas we don't need metric (Score:5, Insightful)
Unfortunately, this thing seems to be en vogue in the computer fashion industry. I just attended a conference where this phrase could some up a bunch of the presentations:
"We are modeling, tapping into the power of social networks, and doing visual analytics!"
I happen to be reading The Psychology of Computer Programming, Silver Anniversary Edition" right now. An interesting quote:
The only thing that's changed here in twenty-five years is the fact that the funds dedicated by executive to eliminating programmers from their payrolls have become far more staggering than I imagined back then. And, now, I finally recognize in this executive desire a pattern so strong, so emotional, that it has blinded these executives to two facts:
1. None of these schemes has succeeded in eliminating programmers . (We have now at least ten times as many as we did then.)
2. Every one of these schemes has been concocted by programmers themselves, the very people the executives want so passionately to eliminate.
So, although people say that programmers lack interpersonal skills, they evidently have a skill at persuasion that surpasses that of the late, great P:T: Barum, famous for his theory: "There's a sucker born every minute."
I guess if I need some money for something from executive, I'll tell them that I need it to model, tap into the power of social networks and do visual analytics. That ought to get me my funds.
Re:Video Speed? (Score:4, Insightful)
Although I don't necessarily agree with your Python joke (pretty funny, though) your comment does provoke me to wonder if Eric really is an "expert" programmer. His eyes go all over the place even when they don't have to. There's only 2 conditions to remember and one "function" (set intersection). His eyes skip all over the place. Further, after the two sets are formed (he's written them in the box and he's already determined what common() does) why is he even looking at the function common() again? Maybe it's to double check, but surely remembering two conditions and a set intersection (3 operations) is well within the grasp of human short-term memory and surely you'd only look at the function name (what it does was verified earlier). Personally after I'd glanced at between() and common() to confirm they did what they suggest they do, I'd never look at them again. But his "expert" eyes keep going back to them while he is forming his output.
Re:This must be a taxpayer-funded experiment (Score:4, Insightful)
when confronted with a situation falling within their specialized field, experts can process information in large chunks. Whereas laymen and novices tend to process things one small piece at a time; and on top of that, they flail around a lot.
Actually, that's a load of nonsense:
1) With programs that are *actually* large, you won't find "experts" that consume them in "large" chunks, unless they use very small fonts.
2) With programs that are new to the readers, you might have to read in toto them anyway. There's no guarantee that the *actual* dependencies in the code will allow you to read it in a limited or strictly hierarchical fashion. You gotta read what you gotta read. It's not like people will only shove neat and pleasurable code on you in real life. If the code is messy, your reading of it will most likely be messy, too. Especially if you hit duplications and have "wait a minute, didn't I see this somewhere else? Lemme check" moments.