Measuring Whitespace Pattern Sequences as an Indication of Plagiarism

There are several methods and technologies for comparing the statements, comments, strings, identifiers, and other visible elements of source code in order to efficiently identify similarity. In a prior paper we found that comparing the whitespace patterns was not precise enough to identify copying by itself. However, several possible methods for improving the precision of a whitespace pattern comparison were presented, the most promising of which was an examination of the sequences of lines with matching whitespace patterns. This paper demonstrates a method of evaluating the sequences of matching whitespace patterns and a detailed study of the method’s reliability.