What Can OSS Mailing Lists Tell Us? A Preliminary Psychometric Text Analysis of the Apache Developer Mailing List

Developer mailing lists are a rich source of information about Open Source Software (OSS) development. The unstructured nature of email makes extracting information difficult. We use a psychometrically-based linguistic analysis tool, the LIWC, to examine the Apache httpd server developer mailing list. We conduct three preliminary experiments to assess the appropriateness of this tool for information extraction from mailing lists. First, using LIWC dimensions that are correlated with the big five personality traits, we assess the personality of four top developers against a baseline for the entire mailing list. The two developers that were responsible for the major Apache releases had similar personalities. Their personalities were different from the baseline and the other developers. Second, the first and last 50 emails for two top developers who have left the project are examined. The analysis shows promise in understanding why developers join and leave a project. Third, we examine word usage on the mailing list for two major Apache releases. The differences may reflect the relative success of each release.