Effects of variable names on comprehension an empirical study.

It is widely accepted that meaningful variable names are important for comprehension. We conducted a controlled experiment in which 9 professional developers try to understand 6 methods from production util classes, either with the original variable names or with names replaced by meaningless single letters. Results show that parameter names are more significant for comprehension than local variables. But, surprisingly, we also found that in 3 of the methods there were no significant differences between the control and experimental groups, due to poor and even misleading variable names. These disturbingly common bad names reflect the subjective nature of naming, and highlight the need for additional research on how variable names are interpreted and how better names can be chosen.