Abstract-Studies have demonstrated the importance of good identifier names to program comprehension. It is unclear, however, whether poor naming has other effects that might impact maintenance effort, e.g. on code quality. We evaluated the quality of identifier names in 8 established open source Java applications libraries, using a set of 12 identifier naming guidelines. We found statistically significant associations between flawed identifiers (i.e. violating at least one guideline) and code quality issues reported by FindBugs, a static analysis tool.

Abstract-Given the importance of identifier names and the value of naming conventions to program comprehension, we speculated in previous work whether a connection exists between the quality of identifier names and software quality. We found that flawed identifiers in Java classes were associated with source code found to be of low quality by static analysis. This paper extends that work in three directions. First, we show that the association also holds at the finer granularity level of Java methods. This in turn makes it possible to, secondly, apply existing method-level quality and readability metrics, and see that flawed identifiers still impact on this richer notion of code quality and comprehension. Third, we check whether the association can be used in a practical way. We adopt techniques used to evaluate medical diagnostic tests in order to identify which particular identifier naming flaws could be used as a light-weight diagnostic of potentially problematic Java source code for maintenance.

Abstract. Identifier names are the main vehicle for semantic information during program comprehension. Identifier names are tokenised into their semantic constituents by tools supporting program comprehension tasks, including concept location and requirements traceability. We present an approach to the automated tokenisation of identifier names that improves on existing techniques in two ways. First, it improves tokenisation accuracy for identifier names of a single case and those containing digits. Second, performance gains over existing techniques are achieved using smaller oracles. Accuracy was evaluated by comparing the output of our algorithm to manual tokenisations of 28,000 identifier names drawn from 60 open source Java projects totalling 16.5 MSLOC. We also undertook a study of the typographical features of identifier names (single case, use of digits, etc.) per object-oriented construct (class names, method names, etc.), thus providing an insight into naming conventions in industrial-scale object-oriented code. Our tokenisation tool and datasets are publicly available 1 .

Abstract-The readability of identifiers is a major factor of program comprehension and an aim of naming convention guidelines. Due to their semantic content, identifiers are also used in feature and bug location, among other software maintenance tasks. Looking at how names are used in practice may lead to insights on potential problems for comprehension and for programming support tools that process identifiers.Class and method names are already well represented in the literature. This paper presents an investigation of Java field, formal argument and local variable names, which we collectively call reference names. These names cannot be ignored because they constitute over half the unique names and almost 70% of the name declarations in the corpus investigated.We analysed the forms of 3.5 million reference name declarations in 60 well known Java projects, examining the phrasal structure of names composed of known words and acronyms. The structures found in practice were evaluated against those given in the literature. The use of unknown abbreviations and words, which may pose a problem for program comprehension, was also identified. Based on our observations of the rich diversity of reference names, we suggest issues to be taken into account for future academic research and for improving tools that rely on names as sources of information.

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