What’s in a Name? A Study of Identifiers

Abstract

Readers of programs have two main sources of domain information: identifier names and comments.When functions are uncommented, as many are, comprehension is almost exclusively dependent on the identifier names. Assuming that writers of programs want to create quality identifiers (e.g., include relevant domain knowledge) how should they go about it? For example, do the initials of a concept name provide enough information to represent the concept? If not, and a longer identifier is needed, is an abbreviation satisfactory or does the concept need to be captured in an identifier that includes full words?Results from a study designed to investigate these questions are reported. The study involved over 100 programmers who were asked to describe twelve different functions. The functions used three different "levels" of identifiers: single letters, abbreviations, and full words. Responses allow the level of comprehension associated with the different levels to be studied.The functions include standard algorithms studied in computer science courses as well as functions extracted from production code. The results show that full word identifiers lead to the best comprehension; however, in many cases, there is no statistical difference between full words and abbreviations.

Physical and conceptual identifier dispersion: Measures and relation to fault proneness

“…They showed that (1) commented programs are more understandable than non-commented programs and (2) programs containing full-word identifiers are more understandable than those with abbreviated identifiers. Similar results have also been achieved by Lawrie et al [22]. Recently, Binkley et al [8] performed an empirical study of the impact of identifier style on code readability and showed that Camelcase identifiers allow more accurate answers.…”

Source Code Analysis: A Road Map

“…Much of this work has a strong focus on program identifiers. For example, IR's cosine similarity has been used to rate the relative quality of modules from within a program producing a semi-automatic quality assessment [74]. Unlike other approaches that consider non-source code documents (e.g., the requirements), this approach focuses exclusively on the code.…”

An Eye Tracking Study on camelCase and under_score Identifier Styles

“…Lawrie et al [18] conduct a large study on identifier names and show that actual words rather than abbreviations lead to better comprehension. Butler et al [6] study the effect of identifier names on the quality of code.…”