g-chapma@gumby.UUCP (04/25/85)
Apropos to this discussion is the report of a study at the University of Maryland on "Program Indentation and Comprehensibility" which ran as a technical note in the category of Human Aspects of Computing in the November 1983 issue of Communications of the ACM. Here's the abstract: The consensus in the progrsmming community is that indentation aids program comprehension, although many studies do not back this up. We tested program comprehension on a Pascal program. Two styles of indentation were used--blocked and nonblocked-- in addition to four possible levels of indentation (0, 2, 4, 6 spaces). Both experienced and novice subjects were used. Although the blocking style made no difference, the level of indentation had a significant effect on program comprehension. (2-4 spaces had the highest mean score for program comprehension.) We recommend that a moderate level of indentation be used to increase program comprehension and user satisfaction. Definitions from the article: "Blocked structures are defined as begin-end blocks of code with inner statements starting in the same column as the begin and end. Non-blocked structures are defined as begin-end blocks of code with inner statements starting at least one level (2, 4, 6 spaces) of indentation to the right of the begin and end."