How Developers Choose Names

TL;DR

This study investigates how developers choose variable and function names, revealing low agreement among developers but high understanding of chosen names, and proposes a three-step model to improve naming quality.

Contribution

The paper introduces a three-step naming model and demonstrates its effectiveness in producing higher-quality, more comprehensive names compared to unstructured naming.

Findings

Low agreement (median 6.9%) among developers on specific names.

Names following the model were judged superior in quality.

Model encourages longer, more concept-rich names.

Abstract

The names of variables and functions serve as implicit documentation and are instrumental for program comprehension. But choosing good meaningful names is hard. We perform a sequence of experiments in which a total of 334 subjects are required to choose names in given programming scenarios. The first experiment shows that the probability that two developers would select the same name is low: in the 47 instances in our experiments the median probability was only 6.9%. At the same time, given that a specific name is chosen, it is usually understood by the majority of developers. Analysis of the names given in the experiment suggests a model where naming is a (not necessarily cognizant or serial) three-step process: (1) selecting the concepts to include in the name, (2) choosing the words to represent each concept, and (3) constructing a name using these words. A followup experiment, using the same experimental setup, then checked whether using this model explicitly can improve the quality of names. The results were that names selected by subjects using the model were judged by two independent judges to be superior to names chosen in the original experiment by a ratio of two-to-one. Using the model appears to encourage the use of more concepts and longer names.